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BEGIN:VEVENT
SUMMARY:Lévy Noise\, Time-Reversal Symmetry\, Nonequilibrium Stochastic T
hermodynamics\, and Bak’s Sandpile
DTSTART;VALUE=DATE-TIME:20201203T160000Z
DTEND;VALUE=DATE-TIME:20201203T162000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-425@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Martin Bier (East Carolina University)\nThe Brownian
noise in nonequilibrium systems commonly contains more outliers. In that
case the noise is best described with a Levy distribution. Many systems in
which there are fluctuations around a steady-state throughput can be mode
led as a Levy-noise-subjected particle in a parabolic potential. We consid
er an overdamped Brownian particle in a parabolic potential. If the noise
is Levy\, time-reversal symmetry for the particle's trajectory is violated
. We formulate a parameter\, r\, to express and detect this violation. Wit
h solar flare data it is shown how r can be readily obtained and next used
to obtain a good estimate of the stability index\, α\, of the underlying
noise. Self-organized-criticality\, i.e. the famous avalanching sandpiles
of Per Bak et al\, can also be modeled with a Levy-noise-subjected partic
le on a potential. Preliminary results from such an approach are shown.\n\
nhttps://zakopane.if.uj.edu.pl/event/16/contributions/425/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/425/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Generalised ‘Arcsine’ laws for run-and-tumble particle in one
dimension
DTSTART;VALUE=DATE-TIME:20201203T172400Z
DTEND;VALUE=DATE-TIME:20201203T172500Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-421@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Prashant Singh (ICTS-TIFR)\nThe ‘Arcsine’ laws o
f Brownian particles in one dimension describe\ndistributions of three qua
ntities: the time $t_m$ to reach maximum position\, the\ntime $t_r$ spent
on the positive side and the time $t_l$ of the last visit to the\norigin.
Interestingly\, the cumulative distribution of all three quantities are th
e\nsame and given by Arcsine function. In this paper\, we study distributi
on of\nthese three times $t_m$\, $t_r$ and $t_l$ in the context of single
run-and-tumble particle\nin one dimension\, which is a simple non-Markovia
n process. We compute\nexact distributions of these three quantities for a
rbitrary time and find that\nall three distributions have a delta function
part and a non-delta function\npart. Interestingly\, we find that the dis
tributions of $t_m$ and tr are identical\n(reminiscent of the Brownian par
ticle case) when the initial velocities of the\nparticle are chosen with e
qual probability. On the other hand\, for $t_l$\, only\nthe non-delta func
tion part is the same as the other two. In addition\, we find\nexplicit ex
pressions of the joint distributions of the maximum displacement\nand the
time at which this maxima occurs.\n\nhttps://zakopane.if.uj.edu.pl/event/1
6/contributions/421/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/421/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Moments of the Van Hove dynamic scattering law
DTSTART;VALUE=DATE-TIME:20201203T172300Z
DTEND;VALUE=DATE-TIME:20201203T172400Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-420@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Ryszard Wojnar (Instytut Podstawowych Problemów Te
chniki PAN)\nStudying the dynamics of a system at the atomic level provide
s important information about the behaviour of the system. For example\, s
tudying the dynamics of enzymes allows us to understand their biological f
unction. Among the available techniques\, studying the dynamics of a syste
m by means of neutron scattering is of exceptional meaning\, as neutrons s
catter at the nuclei themselves.\nVan Hove's functions $G_s(r\,t)$ and $G
_d(r\,t)$\, as well its Fourier transforms $I_s(k\,t)$ and $I_d(k\,t$ cont
ain all accessible information on the dynamics of the system. In order to
find the function $I_s (k\,t)$ for small times we use its lowest time deri
vatives taken at the time $t = 0$. These are also the moments of the scatt
ering law $ S_s (k\,\\omega)$. Moments of the odd orders are equal to zero
\, what results from the invariance of the mechanics equations with respec
t to the time inversion. We give even moments up to the tenth order.\n\nht
tps://zakopane.if.uj.edu.pl/event/16/contributions/420/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/420/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Force spectroscopy in the study of endometrial diseases
DTSTART;VALUE=DATE-TIME:20201203T172200Z
DTEND;VALUE=DATE-TIME:20201203T172300Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-419@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Agnieszka Kurek (Jerzy Haber Institute of Catalysis
and Surface Chemistry\, Polish Academy of Sciences)\, Jakub Barbasz (Jerzy
Haber Institute of Catalysis and Surface Chemistry\, Polish Academy of Sc
iences)\nThe endometrium is the tissue lining the uterus cavity. The most
important role of this tissue is enabling the embryo to implant and provid
ing it with good conditions for growth and development.\nAccording to many
literature reports\, cell and tissue mechanical properties have a signifi
cant role in many disease states. Changes in cell properties such as elast
icity are observed in the case of various cancers or blood diseases.\n The
main technique for cell and tissue mechanical properties analysis is Forc
e Spectroscopy. The force curves obtained during indentation reflect the i
nteraction between the surface of the sample surface and the measuring pro
be. The course of these curves allows the determination of such properties
as adhesion and Young modulus.\n In this poster\, we present results of r
esearch aimed at checking the relationship between Young's modulus of endo
metrial tissue and women’s receptivity.\n\nhttps://zakopane.if.uj.edu.pl
/event/16/contributions/419/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/419/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Super-spreaders in the Corona Epidemics
DTSTART;VALUE=DATE-TIME:20201203T080000Z
DTEND;VALUE=DATE-TIME:20201203T083000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-418@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Kim Sneppen (Niels Bohr Institute)\nRecently a power
ful example of a replicating nano-machinery entered our society. In princi
ple it’s just a normal disease\, that one attempt to model with 3 or 4 s
imple coupled equations with 2 important parameters: a timescale\, and a r
eplication factor (the famous $R_0$). And then one try to guess how change
s in society changes $R_0$ and perhaps adopt some more or less strong lock
-down measures. However\, this virus have more “personality” than that
. It behaves different in different persons\, and persons behave different
ly. Presumably only a few of us infect a lot\, while most does not infect
so much. This assumption is supported by the observation that couples livi
ng together only infect each other with about 15 percent probability\, ind
icating that most infected people are not really infectious. I will discus
s this and other aspects of Covid-19 in perspective of models that describ
e heterogeneous individuals in a society. In particular we suggest that li
miting superspreading opportunities is a cost effective strategy to mitiga
te Covid-19.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributions/418/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/418/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Diffusion limitations and translocation barriers in atomically thi
n biomimetic pores
DTSTART;VALUE=DATE-TIME:20201204T164000Z
DTEND;VALUE=DATE-TIME:20201204T170000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-401@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Michael Zwolak (NIST)\nIonic transport in nano- to s
ub-nano-scale pores is highly dependent on translocation barriers and pote
ntial wells. These features in the free-energy landscape are primarily the
result of ion dehydration and electrostatic interactions. For pores in at
omically thin membranes\, such as graphene\, other factors come into play.
Ion dynamics both inside and outside the geometric volume of the pore can
be critical in determining the transport properties of the channel due to
several commensurate length scales\, such as the effective membrane thick
ness\, radii of the first and the second hydration layers\, pore radius\,
and Debye length. In particular\, for biomimetic pores\, such as the graph
ene crown ether we examine\, there are regimes where transport is highly s
ensitive to the pore size due to the interplay of dehydration and interact
ion with pore charge. Picometer changes in the size\, e.g.\, due to a minu
te strain\, can lead to a large change in conductance. Outside of these re
gimes\, the small pore size itself gives a large resistance even when elec
trostatic factors and dehydration compensate each other to give a relative
ly flat - e.g.\, near barrierless - free energy landscape. The permeabilit
y\, though\, can still be large and ions will translocate rapidly after th
ey arrive within the capture radius of the pore. This\, in turn\, leads to
diffusion and drift effects dominating the conductance. The current thus
plateaus and becomes effectively independent of pore free energy character
istics. Measurement of this effect will give an estimate of the magnitude
of kinetically-limiting features and experimentally constrain the local el
ectromechanical conditions.\n\nhttps://zakopane.if.uj.edu.pl/event/16/cont
ributions/401/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/401/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Biological Networks Regulating Cell Fate Choice Are Minimally Frus
trated
DTSTART;VALUE=DATE-TIME:20201204T162000Z
DTEND;VALUE=DATE-TIME:20201204T164000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-385@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: David Kessler (Bar-Ilan University)\nCharacterizatio
n of the differences between biological and random networks can reveal the
design principles that enable the robust realization of crucial biologica
l functions including the establishment of different cell types. Previous
studies\, focusing on identifying topological features that are present in
biological networks but not in random networks\, have\, however\, provide
d few functional insights. We use a Boolean modeling framework and ideas f
rom the spin glass literature to identify functional differences between f
ive real biological networks and random networks with similar topological
features. We show that minimal frustration is a fundamental property that
allows biological networks to robustly establish cell types and regulate c
ell fate choice\, and that this property can emerge in complex networks vi
a Darwinian evolution. The study also provides clues regarding how the reg
ulation of cell fate choice can go awry in a disease like cancer and lead
to the emergence of aberrant cell types.\n\nhttps://zakopane.if.uj.edu.pl/
event/16/contributions/385/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/385/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Protein noise floor in gene expression: How cell growth and divisi
on contribute to it?
DTSTART;VALUE=DATE-TIME:20201204T160000Z
DTEND;VALUE=DATE-TIME:20201204T162000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-389@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Anna Ochab-Marcinek (Institute of Physical Chemistry
\, Polish Academy of Sciences)\nGene expression in cells is a stochastic p
rocess. Experiments have shown that noise in protein levels does not decre
ase to zero as mean gene expression increases. The origins of the noise fl
oor are still debated. The goal of our study was to check how several basi
c mechanisms affect the noise floor level. These mechanisms are: Cell-cycl
e dependent gene expression\, translational bursting\, random protein part
itioning between daughter cells at division\, and cell cycle desynchroniza
tion resulting in cell-cycle age distribution within the population. Our m
odel gives analytical predictions of the existence of the noise floor and
it semi-quantitatively reproduces the shapes of the experimental noise vs.
protein concentration plots. We show what additional experimental informa
tion is needed for the mean-noise fitting to be unambiguous.\n\n[1] J. Ję
drak\, A. Ochab-Marcinek\, Contributions to the 'noise floor' in gene expr
ession in a population of dividing cells\, Scientific Reports\, 10\, 13533
(2020)\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributions/389/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/389/
END:VEVENT
BEGIN:VEVENT
SUMMARY:On zero-delay synchronization in a network of timed automata model
ing cardiac tissue
DTSTART;VALUE=DATE-TIME:20201204T153000Z
DTEND;VALUE=DATE-TIME:20201204T160000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-368@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Danuta Makowiec (Institute of Theoretical Physics\,
University of Gdańsk)\nA network of timed automata (NTA)\, inspired by Gr
eenberg-Hastings cellular automata\, can efficiently and faithfully reflec
ts the work of the real pacemaker [1]. In this system\, each automaton cy
clically switches between three states of a certain length of time: from $
F$ firing state of length $f$\, to $R$ refractory state of length $r$ a
nd then to $A$ activity state of length $a$\, what closely follows the p
henomenologically known oscillations of myocytes. As a results of interac
tions between neighboring cells\, the self-organization of the oscillating
units to a common oscillation emerges which then leads to forming a signa
l of initiating a contraction of the whole heart. Thus NTA establishes
an appropriate platform to model a natural human pacemaker\, in which we g
ain insight into conditions and stages of the synchronization process [2].
\n\nThe visible effect of synchronization in NTA is the excitation wave\,
i.e. the emergence of steady move of a cluster formed by automata staying
in $F$ state.\nThe synchronization can be of frequency locking type\, when
some automata force the neighboring automata to faster switch the state $
A$ to $F$ than it is expected by intrinsic automaton's cycle\, or of phase
-locking type\, when neighboring automata exhibit the common difference in
oscillatory phase. Thus\, the frequency-locking synchronizations result i
n the fast rhythms. The visible effect of such synchronization is a spiral
origin of the excitation wave. The phase-locking synchronization occurs
when neighboring automata are one step late in the advancement of the cyc
lic transitions of intrinsic time periods. A visible effect of such synchr
onization is propagation of the excitation wave with rhythm comparable to
the period of oscillating automata.\n\nThe strength of synchronization is
due to the reduction of uncorrelated degrees of freedom to a collective m
ode of operation\, which then enables the long-term ordering and coordinat
ion of biological processes\n\nThe emergence of zero-delay phase-locking s
ynchronization\, the marching squad synchronization\, has been observed
in NTA when in response to the $F$ state of neighbors\, the length of the
refractory phase $r$ was increased [1]. \nOn the other hand\, in NTA syst
em in which the vagal regulation was modeled as increase in the length $a$
of the activity state in response to the vagal activity\, such synchroni
zation is also observed but only when the activity of vagal system often
changes [2].\nThe mechanisms behind synchronizing without any delay in s
patially distributed systems are not clear and debated. The presentation w
ill be devoted to analyze possible mechanisms leading to the marching squ
ad synchronization in the NTA system modeling the pacemaker.\n\n\n[1] D. M
akowiec "Pacemeaker rhythm through networks of pacemaker automata - a revi
ew" Acta Physica Polonica B Proceedings Supplement\, 7(2014) 347\n[2] D. M
akowiec\, W. Miklaszewski\, J. Wdowczyk\, A. Lawniczak "From cellular auto
mata model of vagal control of human right atrium to heart beats patterns"
Physica D\, to appear\, (2020)\n\nhttps://zakopane.if.uj.edu.pl/event/16/
contributions/368/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/368/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thermodynamics in biology: From molecular motors to metabolism
DTSTART;VALUE=DATE-TIME:20201204T150000Z
DTEND;VALUE=DATE-TIME:20201204T153000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-403@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Massimiliano Esposito (University of Luxembourg)\nI
will describe recent progress in nonequilibrium thermodynamics based on st
ochastic thermodynamics and chemical reaction network theory. I will discu
ss the relevance of these results for biology and the many open challenges
to be addressed.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributions/
403/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/403/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Continuous time-reversal and the thermodynamic uncertainty relatio
n
DTSTART;VALUE=DATE-TIME:20201204T122000Z
DTEND;VALUE=DATE-TIME:20201204T124000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-395@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Andreas Dechant (Department of Physics I\, Kyoto Uni
versity)\nWe introduce a continuous time-reversal operation which connects
the time-forward and time-reversed trajectories in the steady state of an
irreversible Markovian dynamics via a continuous family of stochastic dyn
amics. This continuous time-reversal allows us to derive a tighter version
of the thermodynamic uncertainty relation (TUR) involving observables eva
luated in different physical systems. Moreover\, the family of dynamics re
alizing the continuous time-reversal contains an equilibrium dynamics half
way between the time-forward and time-reversed dynamics. We show that this
equilibrium dynamics\, together with an appropriate choice of the observa
ble\, turns the inequality in the TUR into an equality. We demonstrate our
findings for the example of a two-dimensional rotational flow and discuss
the role of the observable close to and far from equilibrium.\n\nhttps://
zakopane.if.uj.edu.pl/event/16/contributions/395/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/395/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The role of ergotropy in the quantum thermodynamics
DTSTART;VALUE=DATE-TIME:20201204T124000Z
DTEND;VALUE=DATE-TIME:20201204T130000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-392@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Marcin Łobejko (University of Gdansk)\nErgotropy is
a state function of a density matrix which physical interpretation is the
optimal work that can be extracted through the arbitrary unitary channel.
The concept naturally appears in frameworks with implicit work reservoirs
(e.g. external fields modeled by time-dependent Hamiltonians)\, where\, i
n particular\, the process of charging and discharging of so-called quantu
m batteries is studied. We reveal that the same quantity appears in autono
mous systems with an idealized model of the work reservoir - a quantum wei
ght. Despite similarities between those two approaches\, we reveal a funda
mental difference\, namely the emergence of the locked energy in coherence
s\, i.e. the quantum part of the state that contributes to ergotropy but c
annot be extracted as a work. Furthermore\, we prove the relation between
the ergotropy and free energy\, where the former can be interpreted as a g
eneralization of the latter for systems coupled to finite-size heat baths\
, such that in the thermodynamic limit the total ergotropy of the system a
nd the heat bath approaches the free energy. As a consequence\, we derive
the second kind of locked energy\, due to the finite-size of the bath\, wh
ich is given by the difference of free energy between the global passive s
tate and the corresponding equilibrium state.\n\nhttps://zakopane.if.uj.ed
u.pl/event/16/contributions/392/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/392/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Symmetries and asymmetries of times to complete a chemical cycle
DTSTART;VALUE=DATE-TIME:20201204T120000Z
DTEND;VALUE=DATE-TIME:20201204T122000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-399@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Artem Ryabov (Charles University)\nMeasurements of d
urations of nonequilibrium stochastic processes provide valuable informati
on on underlying microscopic kinetics and energetics. Theories for corresp
onding experiments to date are well-developed for single-particle systems
only. Little is known for interacting systems in nonequilibrium environmen
ts. We introduce and discuss a basic model for cycle processes interacting
with an environment that can be out of thermodynamic equilibrium. We find
a surprising richness of cycle time variations with environmental conditi
ons. This manifests itself in unequal cycle times in forward and backward
cycle directions\, speeding up of backward cycles by interactions\, and dy
namical phase transitions\, where cycle times become multimodal functions
of a bias. The model allows us to relate these effects to specific microsc
opic mechanisms\, which can be helpful for interpreting experiments.\n\nht
tps://zakopane.if.uj.edu.pl/event/16/contributions/399/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/399/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Modeling Echo Chambers and Polarization Dynamics in Social Network
s
DTSTART;VALUE=DATE-TIME:20201204T114000Z
DTEND;VALUE=DATE-TIME:20201204T120000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-384@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Fabian Baumann (Humbold University at Berlin)\nEcho
chambers and opinion polarization recently quantified in several sociopoli
tical contexts and across different social media raise concerns on their p
otential impact on the spread of misinformation and on the openness of deb
ates. Despite increasing efforts\, the dynamics leading to the emergence o
f these phenomena remain unclear. We propose a model that introduces the d
ynamics of radicalization as a reinforcing mechanism driving the evolution
to extreme opinions from moderate initial conditions. Inspired by empiric
al findings on social interaction dynamics\, we consider agents characteri
zed by heterogeneous activities and homophily. We show that the transition
between a global consensus and emerging radicalized states is mostly gove
rned by social influence and by the controversialness of the topic discuss
ed. Compared with empirical data of polarized debates on Twitter\, the mod
el qualitatively reproduces the observed relation between users’ engagem
ent and opinions\, as well as opinion segregation in the interaction netwo
rk. Our findings shed light on the mechanisms that may lie at the core of
the emergence of echo chambers and polarization in social media.\n\nhttps:
//zakopane.if.uj.edu.pl/event/16/contributions/384/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/384/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The q-voter model with attractive and repulsive interactions and i
ndependence on random graphs
DTSTART;VALUE=DATE-TIME:20201204T112000Z
DTEND;VALUE=DATE-TIME:20201204T114000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-400@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Andrzej Krawiecki (Faculty of Physics\, Warsaw Unive
rsity of Technology)\nThe $q$-voter model with both attractive (roughly sp
eaking\, ferromagnetic-like) and repulsive (antiferromagnetic-like) intera
ctions on random graphs is investigated. In this model the agent\, represe
nted by a two-state spin located in a node of a graph\, with probability $
1-p$ changes his/her opinion under the influence of a clique of $q$ random
ly chosen neighbors and with probability $p$ acts independently and change
s opinion randomly. In the former case the agent changes opinion if opinio
ns of all selected neighbors interacting with him/her attractively via the
attached edges of the graph ("friends") are opposite and simultaneously o
pinions of all selected neighbors interacting with him/her repulsively ("d
isliked persons") are the same as the agent's one. The parameter $p$ measu
res the level of stochastic noise in the model. For $q\\ge 4$ the model on
graphs with large mean degree of nodes exhibits first-order ferromagnetic
transition with decreasing $p$\, with a clearly visible hysteresis loop.
The width of this loop decreases with increasing fraction of the repulsive
interactions and the transition can eventually become second-order. For $
q<4$ the transition is always second-order. An extension of the pair appro
ximation taking into account presence of the repulsive interactions predic
ts quantitatively well results of Monte Carlo simulations of the model in
a broad range of parameters.\n\nhttps://zakopane.if.uj.edu.pl/event/16/con
tributions/400/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/400/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Spontaneous symmetry breaking of active phase in coevolving nonlin
ear voter model
DTSTART;VALUE=DATE-TIME:20201204T110000Z
DTEND;VALUE=DATE-TIME:20201204T112000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-383@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Arkadiusz Jędrzejewski (Wrocław University of Scie
nce and Technology)\nA feedback loop between the network topology and dyna
mical processes that occur between nodes is common in real-world networks.
The topology impacts the evolution of node states\, which in turn influen
ce the way the structure itself is modified. This feedback is a signature
of networks that are called adaptive or coevolutionary. Adaptive networks
are especially relevant for social systems\, where they can model phenomen
a such as the emergence of consensus and polarization\, opinion formation\
, or group fragmentation. These coevolutionary models rely on two basic me
chanisms. One accounts for the changes in the node states\, whereas the ot
her for the link rewiring. Both of them may be implemented in various ways
. The voter model\, as a minimalist model of opinion formation process\, p
rovides the basis for the evolution of state variables in many adaptive ne
tworks that represent social interactions. Being analytically tractable\,
it has played a fundamental role in understanding the process of network f
ragmentation. This work extends the study in this area by the analysis of
one of the nonlinear extensions of the coevolving voter model.\n\nIn the a
nalyzed model\, each node in the network represents a voter and can be in
one of two states that correspond to different opinions shared by the vote
rs. A voter disagreeing with its neighbor's opinion may either adopt it or
rewire its link to another randomly chosen voter with any opinion. The sy
stem is studied by means of the pair approximation in which a distinction
between the average degrees of nodes in different states is made. This app
roach allows us to identify two dynamically active phases: a symmetric and
an asymmetric one. The asymmetric active phase\, in contrast to the symme
tric one\, is characterized by different numbers of nodes in the opposite
states that coexist in the network. The pair approximation predicts the po
ssibility of spontaneous symmetry breaking\, which leads to a continuous p
hase transition between the symmetric and the asymmetric active phases. In
this case\, the absorbing transition occurs between the asymmetric active
and the absorbing phases after the spontaneous symmetry breaking. Discont
inuous phase transitions and hysteresis loops between both active phases a
re also possible. Interestingly\, the asymmetric active phase is not displ
ayed by the model where the rewiring occurs only to voters sharing the sam
e opinion\, studied by other authors. Our results are backed up by Monte C
arlo simulations.\n\nDuring the talk\, we will compare both the versions o
f the model\, and we will see how a seemingly small difference in the link
rewiring dynamics leads to profound differences in the phase diagrams exh
ibited by the models.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributi
ons/383/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/383/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Random walks with asymmetric time delays
DTSTART;VALUE=DATE-TIME:20201204T093000Z
DTEND;VALUE=DATE-TIME:20201204T095000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-402@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Jacek Miękisz (University of Warsaw)\nWe study simp
le random-walk models with asymmetric time delays. Probability of a walker
to move to the right or to the left depends on a difference between two s
tate-dependent functions evaluated at states of the walker at two differen
t times in the past. This might be seen as a model of a discrete replicato
r dynamics with strategy-dependent time delays. We assume hyperbolic-tange
nt fitness functions and to obtain analytical results we approximate them
by step functions. \n\nWe observe a novel behavior. Namely\, the mean posi
tion of the walker depends on time delays. This is a joint effect of stoch
asticity and time delays present in the system. In the deterministic versi
on of a hyperbolic-tangent model\, there appear symmetric cycles around a
stationary point so the mean position of the walker stays the same. In sto
chastic versions without time delays\, the expected value of the position
of the walker is given by the stationary point.\n \nIf one interprets a po
sition of the walker as a fraction of the population with a given strategy
\, then our results show that this fraction is a decreasing function of a
delay\, in fact a linear one for small delays. Moreover\, bigger is the re
gion with the (almost) unbiased random walk\, smaller is the fraction of t
he population of the strategy with a bigger time delay.\n\nhttps://zakopan
e.if.uj.edu.pl/event/16/contributions/402/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/402/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effective Langevin equations leading to large deviation function o
f time-averaged velocity for a nonequilibrium Rayleigh piston
DTSTART;VALUE=DATE-TIME:20201204T091000Z
DTEND;VALUE=DATE-TIME:20201204T093000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-386@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Masato Itami (Nagoya University)\nWe study fluctuati
ng dynamics of a freely movable piston that separates an infinite cylinder
into two regions filled with ideal gas particles at the same pressure but
different temperatures. To investigate statistical properties of the time
-averaged velocity of the piston in the long-time limit\, we perturbativel
y calculate the large deviation function of the time-averaged velocity. Th
en\, we derive an infinite number of effective Langevin equations yielding
the same large deviation function as in the original model. Finally\, we
provide two possibilities for uniquely determining the form of the effecti
ve model.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributions/386/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/386/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geometrical Optics of Constrained Brownian Motion
DTSTART;VALUE=DATE-TIME:20201204T085000Z
DTEND;VALUE=DATE-TIME:20201204T091000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-398@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Baruch Meerson (Hebrew University of Jerusalem)\nThe
optimal fluctuation method — essentially geometrical optics — gives a
valuable insight into large deviations of constrained Brownian motion\, a
nd it achieves this purpose by simple means. I will illustrate these poin
ts by revisiting the Airy distribution - the probability distribution of t
he \narea under a Brownian excursion - and considering some additional sta
tistics of Brownian excursions. \n\nThe geometrical optics immediately giv
es the large-area tail of the Airy distribution. It also predicts the posi
tion distribution of a Brownian excursion at an intermediate time\, condit
ioned on a large area. Finally\, it gives the area distribution on a sub-
interval of Brownian excursion. The last two distributions exhibit dynamic
al phase transitions which have a simple geometric origin.\n\nhttps://zako
pane.if.uj.edu.pl/event/16/contributions/398/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/398/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anomalous Diffusion and Generalized Cattaneo Equation
DTSTART;VALUE=DATE-TIME:20201204T083000Z
DTEND;VALUE=DATE-TIME:20201204T085000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-388@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Katarzyna Gorska (Institute of Nuclear Physics\, Pol
ish Academy of Sciences)\nThe generalized Cattaneo equation (GTE) involvin
g memory effect is introduced by smearing the time derivatives. Consistenc
y conditions which the smearing functions obey restrict freedom in their c
hoice. The proposed scheme goes beyond the approach based on using fractio
nal derivatives. I present the conditions under which solutions of the GTE
can be recognized as probability distribution\, i.e. are normalizable and
nonnegative on their domain.\n\nhttps://zakopane.if.uj.edu.pl/event/16/co
ntributions/388/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/388/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Galilean invariance for stochastic diffusive dynamics
DTSTART;VALUE=DATE-TIME:20201204T080000Z
DTEND;VALUE=DATE-TIME:20201204T083000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-369@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Rainer Klages (Queen Mary University of London)\nGal
ilean invariance is a cornerstone of classical mechanics. It states that t
he equations of motion are the same in different inertial frames meaning t
hey do not change under a Galilean transformation. Inertial frames\, in tu
rn\, are reference frames describing closed systems where the frame-intern
al physics is not affected by frame-external forces. The description of re
al world systems\, however\, usually requires coarse-grained models integr
ating complex internal and external interactions indistinguishably as fric
tion and stochastic forces\, which intrinsically violates Galilean invaria
nce. Starting from the Kac-Zwanzig Hamiltonian for a tracer particle in a
heat bath of harmonic oscillators generating Brownian motion\, we show how
Galilean invariance is broken during the coarse graining procedure when d
eriving stochastic Langevin dynamics. We argue that traces of Galilean inv
ariance survive for stochastic dynamics yielding a set of alternative rule
s\, which we call weak Galilean invariance.\n\n[1] A.Cairoli\, R.Klages\,
A.Baule\, Weak Galilean invariance as a selection principle for coarse-gra
ined diffusive models\, PNAS 115\, 5714 (2018)\n\nhttps://zakopane.if.uj.e
du.pl/event/16/contributions/369/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/369/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pre-poster session
DTSTART;VALUE=DATE-TIME:20201203T164000Z
DTEND;VALUE=DATE-TIME:20201203T170000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-417@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Paweł Góra (Jagiellonian University)\nhttps://zako
pane.if.uj.edu.pl/event/16/contributions/417/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/417/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simple mathematical models for self-propelled motion on the water
surface.
DTSTART;VALUE=DATE-TIME:20201203T162000Z
DTEND;VALUE=DATE-TIME:20201203T164000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-387@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Jerzy Gorecki (ICHF PAN)\nSelf-propelled motion on t
he water surface has fascinated scientists for almost two hundred years. T
here are many solid substances\, such as camphor\, camphene\,\nand phenant
hroline\, which can develop to the water surface as a molecular layer\, ev
aporate to the air phase and continuously dissolve into the water phase. T
his surface layer decreases the water surface tension and this decrease is
local and time-dependent. Inhomogeneities in the surface concentration\,
resulting from fluctuations in release and evaporation\, can break the sy
mmetry around an object and drive its motion. The mathematical descriptio
n of the self-propelled motion is complex because it should include object
location\, generated hydrodynamic flows\, and dissipation of surface-acti
ve molecules. The simplest mathematical models consider the object positio
n together with the concentration of surface-active molecules described by
a reaction-diffusion equation in which the effective diffusion coefficien
t includes a hydrodynamic effect. However\, \nthere are many interesting
examples of systems where the motion of a self-propelled object is strongl
y coupled with generated hydrodynamic flows and in such cases\, the model
mentioned above fails. We introduce another simple mathematical model that
describes the time evolution of a self-propelled object on a liquid surfa
ce using such variables as the object location\, the surface concentration
of active molecules\, and the hydrodynamic surface flow. The model is app
lied to simulate the time evolution of a rotor composed of a polygonal pla
te with camphor pills at its corners. We have qualitatively reproduced res
ults of experiments\, in which the inversions of rotational direction unde
r periodic stop- and release- operations were investigated. The model corr
ectly describes the probability of the inversion as a function of the dura
tion of the phase when the rotor is stopped. Moreover\, the model allows u
s to introduce the rotor asymmetry unavoidable in real experiments and stu
dy its influence on the studied phenomenon. Our numerical simulations have
revealed that the probability of the inversion of rotational direction is
determined by the competition among the transport of the camphor molecule
s by the flow\, the intrinsic asymmetry of the rotor\, and the noise ampli
tude.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributions/387/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/387/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Optimization and Growth in First-Passage Resetting
DTSTART;VALUE=DATE-TIME:20201203T150000Z
DTEND;VALUE=DATE-TIME:20201203T153000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-366@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Sidney Redner (Santa Fe Institute)\nWe combine reset
ting and first-passage to define "first-passage resetting”\, where a ran
dom walk is reset to a fixed position due to a first-passage event of the
walk itself. On the infinite half-line\, first-passage resetting of isotr
opic diffusion is non-stationary\, in which the number of resetting events
grows with time as $t^{1/2}$. We calculate the resulting spatial probabi
lity distribution of the particle\, and also obtain this distribution by a
path decomposition approach. In a finite interval\, we define an first-pa
ssage-resetting optimization problem that is motivated by reliability theo
ry. Here\, the goal is to operate a mechanical system close to its maximu
m capacity without experiencing too many breakdowns. When a breakdown occ
urs\, the system is reset to its minimal operating point. We define and op
timize an objective function that maximizes the reward (being close to max
imum operation) minus a penalty for each breakdown. Finally\, we study a
first-passage-driven domain growth dynamics in which its boundary recedes
by a specified amount when a diffusing particle reaches the boundary\, aft
er which resetting occurs. We find a wide range of dynamical behaviors for
the domain growth rate in the interval and the semi-infinite line.\n\nhtt
ps://zakopane.if.uj.edu.pl/event/16/contributions/366/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/366/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Restart: The Physics Of Starting Anew
DTSTART;VALUE=DATE-TIME:20201203T153000Z
DTEND;VALUE=DATE-TIME:20201203T160000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-364@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Shlomi Reuveni (Tel Aviv University)\nStopping a pro
cess in its midst—only to start it all over again—may prolong\, leave
unchanged\, or even shorten the time taken for its completion. Among these
three possibilities\, the latter is particularly interesting as it sugges
ts that restart can be used to expedite the completion of complex processe
s involving strong elements of chance. This turned out to be important in
computer science where restart drastically improves performance of randomi
zed algorithms\, but is not less relevant to many physical\, chemical\, an
d biological processes where restart plays a central role. In this talk\,
I will provide an introduction to the theory of restart phenomena and revi
ew some of its applications in statistical\, chemical\, and biological phy
sics. \n\nReferences\n\n[1] S. Reuveni\, Phys. Rev. Lett. **116**\, 170601
(2016).\n[2] A. Pal & S. Reuveni\, Phys. Rev. Lett. **118**\, 030603 (201
7).\n[3] A. Pal\, I. Eliazar & S. Reuveni\, Phys. Rev. Lett. **122**\, 020
602 (2019).\n[4] S. Ray\, D. Mondal & S. Reuveni\, J. Phys. A. **52**\, 25
5002 (2019).\n[5] S. Ray & S. Reuveni\, J. Chem. Phys. **152**\, 234110 (2
020).\n[6] O. T. Friedman\, A. Pal\, A. Sekhon\, S. Reuveni & Y. Roichman\
, J. Phys. Chem. Lett. **11**\, 7350 (2020).\n[7] A. Pal\, Ł. Kuśmierz &
S. Reuveni\, Phys. Rev. Research **2**\, 043174 (2020).\n\nhttps://zakopa
ne.if.uj.edu.pl/event/16/contributions/364/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/364/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Variational Approach to KPZ: Fluctuation Theorems\, Large Deviatio
n Function\, and Probability Distribution Function
DTSTART;VALUE=DATE-TIME:20201203T123000Z
DTEND;VALUE=DATE-TIME:20201203T125000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-393@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Horacio S. Wio (Inst.Fisica Interdisc.&Sist.Compl.)\
nThe KPZ equation is - as known - a stochastic field theory that describes
the kinetic roughening of surfaces and interfaces\, plus many other noneq
uilibrium processes that belong to its universality class. For $\\lambda\\
neq 0$\, the systems described are intrinsically unstable and "lack of sta
tionary probability distribution". This can be readily inferred from the s
tructure of the functional from which the deterministic KPZ equation stems
in a variational formulation [1]. In fact\, the time behavior of the afor
ementioned functional resembles that of a particle in a gravitational fiel
d [2]. A path-integral scheme has been set up in [3] that allows obtaining
detailed and integral fluctuation theorems - as well as a Large Deviation
Function for entropy production - for the KPZ equation\, "regardless of t
he substrate dimensionality" [4]. After reviewing these issues\, we close
by discussing an explicit expression of the probability distribution for t
he KPZ system.\n\n[1] H.S. Wio\, "Variational formulation for the KPZ and
related kinetic equations"\, Int. J. Bif. Chaos 19\, (2009) 2813-2821.\n[2
] H.S. Wio\, M.A.Rodriguez\, R.Gallego\, J.A.Revelli\, A. Ales and R.R.De
za\, "d-Dimensional KPZ Equation as a Stochastic Gradient Flow in an Evolv
ing Landscape: Interpretation and Time Evolution of Its Generating Functio
nal"\, Front.Phys.4 (2017): 52.\n[3] H.S. Wio\, R.R. Deza and J.A. Revelli
\, "Fluctuation theorems and large deviation functions in systems not feat
uring a steady state"\, J. Stat. Mech. (2020) 024009.\n[4] H.S. Wio\, M.A.
Rodriguez and R. Gallego\, "Variational approach to KPZ: Fluctuation theo
rems and large deviation function for entropy production"\, Chaos 30\, (20
20) 073107.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributions/393/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/393/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Confined random motion: What is statistics? Gaussian or Laplacian?
DTSTART;VALUE=DATE-TIME:20201203T121000Z
DTEND;VALUE=DATE-TIME:20201203T123000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-397@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Aleksander Stanislavsky ()\nIn biophysics\, the sing
le-particle tracking (SPT) is broadly used to quantify the kinetics of flu
orescently-labelled molecules/proteins in live cells. This powerful tool i
n microscopy permits ones to resolve modes of motion of individual molecul
es for better understanding their role in such systems. The motion is not
limited to pure (Brownian motion) diffusion\, but directed\, confined\, an
omalous diffusion are observed too. The study of their effects in live cel
ls is of great interest.\n Based on strict analytical calculations an
d simulations\, we show that the confined motion in presence of Brownian m
otion in complex systems may have two different statistics . One of them h
as the normal distribution\, whereas another\, surprisingly\, is under the
Laplace distribution with fatter tails than the normal case (with thin ta
ils always). Using the experimental data obtained from a recent SPT study
on two particle types\, G-protein coupled receptors and the G proteins wit
h which the receptors interact\, we have detected the normal and Laplace c
onfinements. It is interesting that the contribution of the Laplace confin
ement is different for G proteins and receptors.\n The results are an
important step to experimental cell probing and paves the way for a new s
trategy acting on the processes occurring in live cells through changing t
he confined motion of molecules into live cells\, for example\, by drugs.
This analytic treatment can be used for different models\, thus opening a
new direction towards understanding the role of confinement in complex sys
tems.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributions/397/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/397/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Extreme-Value Statistics of Stochastic Transport Processes
DTSTART;VALUE=DATE-TIME:20201203T115000Z
DTEND;VALUE=DATE-TIME:20201203T121000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-391@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Alexandre Guillet ()\nWe derive exact expressions fo
r the finite-time statistics of extrema (maximum and minimum) of the spati
al displacement and the fluctuating entropy flow of biased random walks. O
ur approach captures key features of extreme events in molecular motor mot
ion along linear filaments. For one-dimensional biased random walks\, we d
erive exact results which tighten bounds for entropy production extrema ob
tained with martingale theory and reveal a symmetry between the distributi
on of the maxima and minima of entropy production. Furthermore\, we show t
hat the relaxation spectrum of the full generating function\, and hence of
any moment\, of the finite-time extrema distributions can be written in t
erms of the Mar{\\v{c}}enko-Pastur distribution of random-matrix theory. U
sing this result\, we obtain efficient estimates for the extreme-value sta
tistics of stochastic transport processes from the eigenvalue distribution
s of suitable Wishart and Laguerre random matrices. We confirm our results
with numerical simulations of stochastic models of molecular motors.\n\nh
ttps://zakopane.if.uj.edu.pl/event/16/contributions/391/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/391/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Loopy Lévy flights enhance tracer diffusion in active suspensions
DTSTART;VALUE=DATE-TIME:20201203T113000Z
DTEND;VALUE=DATE-TIME:20201203T115000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-412@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Adrian Baule ()\nBrownian motion is widely used as a
model of diffusion in equilibrium media throughout the physical\, chemica
l and biological sciences. However\, many real-world systems are intrinsic
ally out of equilibrium owing to energy-dissipating active processes under
lying their mechanical and dynamical features. The diffusion process follo
wed by a passive tracer in prototypical active media\, such as suspensions
of active colloids or swimming microorganisms\, differs considerably from
Brownian motion\, as revealed by a greatly enhanced diffusion coefficient
and non-Gaussian statistics of the tracer displacements. Although these c
haracteristic features have been extensively observed experimentally\, the
re is so far no comprehensive theory explaining how they emerge from the m
icroscopic dynamics of the system. Here we develop a theoretical framework
to model the hydrodynamic interactions between the tracer and the active
swimmers\, which show s that the tracer follows a non-Markovian coloured P
oisson process that accounts for all empirical observations [1]. The theor
y predicts a long-lived Lévy flight regime of the loopy tracer motion wit
h a non-monotonic crossover between two different power-law exponents. The
duration of this regime can be tuned by the swimmer density\, suggesting
that the optimal foraging strategy of swimming microorganisms might depend
crucially on their density in order to exploit the Lévy flights of nutri
ents. Our framework can be applied to address important theoretical questi
ons\, such as the thermodynamics of active systems\, and practical ones\,
such as the interaction of swimming microorganisms with nutrients and othe
r small particles (for example\, degraded plastic) and the design of artif
icial nanoscale machines.\n\n[1] K. Kanazawa\, T. Sano\, A. Cairoli\, A. B
aule\; Nature 579\, 364–367 (2020)\n\nhttps://zakopane.if.uj.edu.pl/even
t/16/contributions/412/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/412/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Packets of diffusing particles exhibit universal exponential tails
DTSTART;VALUE=DATE-TIME:20201203T110000Z
DTEND;VALUE=DATE-TIME:20201203T113000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-363@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Eli Barkai (Bar Ilan Univeristy)\nBrownian motion is
a Gaussian process described by the central limit theorem. How- ever\, ex
ponential decays of the positional probability density function $P(X\, t)$
of packets of spreading random walkers\, were observed in numerous situat
ions that include glasses\, live cells\, and bacteria suspensions. We show
that such exponential behavior is generally valid in a large class of pro
blems of transport in random media. By extending the large deviations appr
oach for a continuous time random walk\, we uncover a general universal be
havior for the decay of the density [1]. It is found that fluctuations in
the number of steps of the random walker\, performed at finite time\, lead
to exponential decay (with logarithmic corrections) of $P(X\, t)$. This u
niversal behavior also holds for short times\, a fact that makes experimen
tal observations readily achievable. Time permitting we then formulate the
hitchhiker model where interacting molecules form aggregates\, that lead
to fluctuations in the diffusion field\, and a many body mechanism for the
exponential tails [2].\n\nReferences\n[1] E. Barkai and Stas Burov\, Pack
ets of diffusing particles exhibit universal exponential tails\, Phys. Rev
. Lett. **124**\, 060603 (2020).\n[2] M. Hidalgo-Soria\, and E. Barkai\, T
he Hitchhiker model for Laplace diffusion processes in the cell environmen
t\, Phys. Rev. E **102**\, 012109 (2020).\n\nhttps://zakopane.if.uj.edu.p
l/event/16/contributions/363/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/363/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Spectral content of a single trajectory
DTSTART;VALUE=DATE-TIME:20201203T093000Z
DTEND;VALUE=DATE-TIME:20201203T100000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-367@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Gleb Oshanin (Theoretical Condensed Matter\, Sorbonn
e Universités / CNRS)\nIn this presentation I will overview a recent prog
ress in the theoretical\, numerical and experimental analyses of spectral
densities of individual random trajectories of a finite length. On example
of a broad class of anomalous diffusions - the so-called fractional Brown
ian motion\, I will demonstrate that one may calculate analytically the fu
ll probability density function of such random functionals\, parametrised
by a frequency and a finite observation time\, and extract a very meaningf
ul information on the evolution of a process under study. In particular\,
I will show that the large frequency behaviour of the coefficient of varia
tion of this distribution provides a robust criterion of anomalous diffusi
on\, which analytical prediction is validated by a comparison with experim
ents on dynamics in live cells and in agarose hydrogels\, and also by exte
nsive numerical simulations. If time permits\, I will also discuss the p
eculiarities of spectra in out-of-equilibrium systems\, as exemplified by
a Brownian Gyrator model\, and also of the so-called active Brownian motio
n.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributions/367/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/367/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Energy cascade in internal wave attractors
DTSTART;VALUE=DATE-TIME:20201203T090000Z
DTEND;VALUE=DATE-TIME:20201203T093000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-362@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Thierry Dauxois (CNRS & ENS de Lyon)\nInternal gravi
ty waves play a primary role in geophysical fluids : they contribute signi
ficantly to mixing in the ocean and they redistribute energy and momentum
in the middle atmosphere. In addition to their very interesting and very u
nusual theoretical properties\, these waves are linked to one of the impor
tant questions in the dynamics of the oceans: the cascade of mechanical en
ergy in the abyss and its contribution to mixing. Combining the physics of
waves\, dynamical systems theory and oceanography\, I will discuss a uniq
ue self-consistent experimental and numerical setup that models a cascade
of triadic interactions transferring energy from large-scale monochromatic
input to multi-scale internal wave motion. I will also provide explicit e
vidence of a wave turbulence framework for internal waves.\n\nhttps://zako
pane.if.uj.edu.pl/event/16/contributions/362/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/362/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Using stochastic models to describe the coronavirus epidemic
DTSTART;VALUE=DATE-TIME:20201203T083000Z
DTEND;VALUE=DATE-TIME:20201203T090000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-406@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Adam Kleczkowski (Univ. of Strathclyde)\nIn December
2019\, a novel new strain of coronavirus (COVID-19) was identified as it
spread through China and subsequently throughout the world\, resulting in
a pandemic. As the health systems became overwhelmed\, a need arose for re
al-time surveillance and modelling to identify the breaking points caused
by increased numbers of infections and hospitalised individuals. We combin
ed surveillance data for Scotland\, detailing new COVID-19 cases\, deaths\
, hospitalisations and critical care beds\, with a modified stochastic Sus
ceptible Exposed Infected Recovered Hospitalised Critical Dead (SEIR-HCD)
model. The model parameters are adjusted daily\, to fit the real-world dat
a\, using a Bayesian statistical particle filtering technique. The estimat
ion technique uses an acceptance/rejection method combined with correlated
multi-dimensional diffusion and drift model to effectively search the par
ameter space. We show close agreement between data and model output and di
scuss how changes in parameters reflect the changing transmission dynamics
of the virus and severity of the disease.\n\nhttps://zakopane.if.uj.edu.p
l/event/16/contributions/406/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/406/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Determination of psychotic behaviour using a network of chemical o
scillators
DTSTART;VALUE=DATE-TIME:20201203T172100Z
DTEND;VALUE=DATE-TIME:20201203T172200Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-357@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Ashmita Bose (Institute of Physical chemistry\,Polis
h Academy of sciences)\nSchizophrenia is the most common form of psychotic
behaviour where patients experiences hallucination\, dillusion or chaotic
speech. Schizophrenia is difficult to detect and easily go undetected for
years. Here we propose the idea of detecting schizophrenia by a network o
f interacting chemical oscillators. We optimized a classifier based on six
interacting oscillator using genetic algorithm and obtained 82% accuracy
of schizophrenia detection on a selected training dataset.\n\nKeywords: S
chizophrenia\, EEG signal\, chemical computing\, oscillatory network\, Ore
gonator model\, genetic optimization\n\nhttps://zakopane.if.uj.edu.pl/even
t/16/contributions/357/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/357/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Experimental study of the energy flux between two NESS thermostats
.
DTSTART;VALUE=DATE-TIME:20201203T172000Z
DTEND;VALUE=DATE-TIME:20201203T172100Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-371@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Antoine Naert (ENS - Lyon\, France)\nWe address the
question of energy transport in out-of-equilibrium systems. The experiment
consists in two coupled granular gas Non-Equilibrium Steady State (NESS)
heat baths\, in which $2$ cm-scale rotors are imbedded. These Brownian-lik
e mobiles are electro-mechanically coupled with a resistor R\, allowing en
ergy to flow between them. The mean flux is non-zero if the temperatures o
f the baths differ. The resistor R allows measurement of the flux and the
temperatures in each bath simultaneously. Varying $R$\, we show that\, in
the limit of non-dissipative coupling ($R\\rightarrow 0$)\, the heat flux
obey the ‘eXchange Fluctuation Theorem’ (XFT)\, in a form proposed by
Jarzynski and Wojcik in $2004$\, for the fluctuations of the flux between
finite size equilibrium heat baths. This result\, here obtained for granul
ar gas thermostats experiment\, is nevertheless representative of a large
class of NESS systems.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contribut
ions/371/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/371/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Steady oscillations in kinetic model of aggregation process with c
ollisional fragmentation
DTSTART;VALUE=DATE-TIME:20201203T171900Z
DTEND;VALUE=DATE-TIME:20201203T172000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-372@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Sergey Matveev (Skolkovo Institute of Science and Te
chnology)\nIn this work\, we study a kinetic model of aggregation process
with collisional fragmentation with use of two efficient implementations o
f numerical methods: direct simulation Monte Carlo and finite-difference s
cheme exploiting the low-rank matrix representations of the utilized kinet
ic coefficients. We concentrate our efforts on the analysis of the solutio
ns for a particular class of non-local aggregation kernels \n$$\nK_{i\,j}
= i^a j^{-a} + i^{-a} j^{a}\,\n$$\nwith multiplicative expression for the
fragmentation rates $F_{i\,j} = \\lambda K_{i\,j}$ with $0 < \\lambda \\ll
1$. For $a > 0.5$ and $\\lambda < \\lambda_{c}$ never-ending collective o
scillations of the aggregates' concentrations take place[1].\n\nThe main c
ontribution of this work is cross-validation of our previous observations
with the utilization of the well-known stochastic acceptance-rejection met
hod [2] and its modification to an accounting of the fragmentation events.
\n\n[1] Brilliantov N. V.\, Otieno W.\, Matveev S. A.\, Smirnov A. P.\, Ty
rtyshnikov E. E.\, Krapivsky P. L. (2018) // Steady oscillations in aggreg
ation-fragmentation processes. Physical Review E\, 98(1)\, 012109.\n[2] Ga
rcia A. L.\, Van Den Broeck C.\, Aertsens M.\, Serneels R. (1987) // A Mon
te Carlo simulation of coagulation. Physica A: Statistical Mechanics and i
ts Applications\, 143(3)\, 535-546.\n\nhttps://zakopane.if.uj.edu.pl/event
/16/contributions/372/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/372/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Finite element modelling of atomic force indentation of an animal
cell
DTSTART;VALUE=DATE-TIME:20201203T171800Z
DTEND;VALUE=DATE-TIME:20201203T171900Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-408@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Leszek Krzemien (Instytut Katalizy i Fizykochemii Po
wierzchni im. Jerzego Habera Polskiej Akademii Nauk)\nWe present a model o
f atomic force microscope indentation measurements using the finite elemen
t method. The focus is set on a thorough representation of the complex str
ucture of an animal cell. Crucial constituent is the cell cortex — a sti
ff layer of cytoplasmic proteins present on the inner side of the cell mem
brane. It plays a vital role in the mechanical interactions between cells.
In our model\, the cell cortex is modelled by a three-dimensional solid c
haracterized primarily by its bending stiffness. This approach allows us t
o interpret the measurements of the mechanical properties of the cells\, s
uch as elasticity. During the simulations\, we probe a broad range of para
meters defining cell properties and experimental conditions. Finally\, we
derive a simple and closed-form formula that approximates the simulated re
sults with satisfactory accuracy. Our formula is as easy to use as Hertz's
function in order to extract cell properties from the measurement\, with
additional consideration of the cell inner structure.\n\nhttps://zakopane.
if.uj.edu.pl/event/16/contributions/408/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/408/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Diffusion-controlled reactions: Extension of time-dependent Smoluc
howski’s rate coefficient to reactions in media with relaxation
DTSTART;VALUE=DATE-TIME:20201203T171700Z
DTEND;VALUE=DATE-TIME:20201203T171800Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-382@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Sergey Traytak (N.N. Semenov Federal Research Center
for Chemical Physics\, Russian Academy of Sciences)\nProcesses involving
Brownian motion of small reactants toward much larger static particles (si
nks) and subsequent trapping of these reactants by the sinks are very comm
only encountered in both nature and in artificial media. Theoretically the
se processes are described by so-called trapping model of the irreversible
bulk diffusion-controlled reactions. To avoid difficulties of classical d
iffusion theory the hyperbolic diffusion approximation is often used [1\,
2]. Within the scope of the telegrapher equation the density distribution
of reactants $\\rho (r\, t)$ about a spherical sink of radius $R$ obeys
the initial boundary-value problem with Smoluchowski’s condition on the
reaction surface [1]. The primary task for the theory of diffusion-control
led reactions is the calculation of the reaction rate coefficient:\n\\begi
n{equation}\nk\\left(t\\right) = k_S \\frac{R}{\\tau_d}\\int_0^t \\exp \\l
eft(-\\frac{t-\\zeta}{\\tau_d}\\right) \\left. \\frac{\\partial \\rho \\le
ft(r\,\\zeta\\right)}{\\partial r} \\right| _{r\\rightarrow R+} d\\zeta .
\n\\end{equation}\nHereafter $k_S=4\\pi RD$ is the Smoluchowski steady sta
te rate coefficient\; $\\tau_d $ and $D$ are the relaxation time for the
gradients of density distribution of reactants and diffusion coefficient\
, respectively. We solved the posed problem exactly and\, using expression
(\\ref{Tray1})\, for the time-dependent reaction rate coefficient obtaine
d\n\\begin{equation}\nk \\left(t\\right) = k_S \\left\\lbrace \\left[1-{\
\exp \\left(- \\frac{t}{\\tau_d} \\right)}\\right] + \\frac{R}{\\sqrt{\\ta
u_d D}}\\left[ \\exp \\left( - \\frac{t}{2\\tau_d} \\right) I_0\\left(\\fr
ac{t}{2\\tau_d} \\right)-{\\exp \\left(- \\frac{t}{\\tau_d} \\right)} \\ri
ght] \\right\\rbrace \,\n\\end{equation}\nwhere $I_0(z)$ is the first kin
d modified Bessel function of order zero. It is important to note that the
last term in expression (1) was erroneously omitted in the relevant formu
la derived by Rice (see expression (289) in page 330 of book [1]). Formula
(2) generalizes the classical Smoluchowski result to short time values\,
which is important for reactions occuring in media with relaxation [2].\n\
n[1] S. A. Rice\, Diffusion-limited reactions\, Amsterdam: Elsevier\, 1985
.\n[2] D. Jou\, J. Casas-Vazquez and G. Lebon\, Extended irreversible ther
modynamics (Fourth Edition)\, Springer\, 2010.\n\nhttps://zakopane.if.uj.e
du.pl/event/16/contributions/382/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/382/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The study of structure influence on diffusion across alginate memb
ranes filled with magnetite
DTSTART;VALUE=DATE-TIME:20201203T171600Z
DTEND;VALUE=DATE-TIME:20201203T171700Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-360@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Anna Strzelewicz (Silesian University of Technology)
\nThe combination of polymer and inorganic substance in hybrid membrane re
sults in favourable selectivity and permeability\, and consequently such m
embrane becomes a promising alternative to conventional membrane materials
. The resulting membranes show improved chemical\, mechanical\, and therma
l stability and hydrophilic–hydrophobic balance. The objective of this r
esearch is to determine whether there is a relation between membrane morph
ology\, which is characterized by different parameters\, and the diffusive
transport in the membrane. We expect that different amount of magnetite p
articles in alginate matrix cross-linked by different agents influence on
structure and morphology properties and also affects the diffusion and tra
nsport properties. In this work\, we investigate the morphology of cross-s
ections of the hybrid alginate membranes filled with various amount of mag
netite $(Fe_3 O_4)$ and crosslinked using four different agents: calcium c
hloride\, phosphoric acid\, glutaraldehyde and citric acid. A key aspect o
f showing structure - diffusion relationship can be the study of the simul
ation of particle motion in a membrane environment\, and in our case\, it
is a simulation of a random walk on the structures of hybrid alginate memb
ranes. For a better understanding of the problem\, we model structures of
two–dimensional heterogenic membranes which resemble real structures and
then simulate random walk on them. The prototype structures of hybrid pol
ymeric membranes are created with the desired quantity\, size and distribu
tion of obstacles\, which corresponds to the given amount of magnetite in
the hybrid alginate membrane. Generated membranes possessing specific para
meters are comparable to the real hybrid alginate membranes filled with ma
gnetite and give a real chance to find the relation between diffusion and
structure properties. This observation may support a better understanding
of structure influence on mass transport through polymer materials.\n\n[1]
G. Dudek\, M. Krasowska\, R. Turczyn\, M. Gnus\, A. Strzelewicz\, Structu
re\, morphology and separation efficiency of hybrid Alg/$Fe_3O_4$ membrane
s in pervaporative dehydration of ethanol\, Separation and Purification Te
chnology 182 (2017) 101–109\n[2] M. Krasowska\, A. Strzelewicz\, G. Dude
k\, M. Cieśla\, Structure-diffusion relationship of polymer membranes wit
h different texture\, Physical Review E 95\, 012155 (2017)\n[3] A. Strzele
wicz\, M. Krasowska\, G. Dudek\, M. Cieśla\, Design of polymer membrane m
orphology with prescribed structure and diffusion properties\, Chemical Ph
ysics\, 531\, 110662 ( 2020)\n\nhttps://zakopane.if.uj.edu.pl/event/16/con
tributions/360/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/360/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cyclic Kuramoto models and Byzantine attack
DTSTART;VALUE=DATE-TIME:20201203T171500Z
DTEND;VALUE=DATE-TIME:20201203T171600Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-359@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Paweł Góra (Jagiellonian University)\nCyclic\, one
-dimensional Kuramoto models with various types of interactions are review
ed. Ruch models are less resilient to Byzantine perturbations than a class
ic solution would suggest.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contr
ibutions/359/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/359/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Combinatorial aspects of the scattering on the Dirac delta potenti
al
DTSTART;VALUE=DATE-TIME:20201203T171400Z
DTEND;VALUE=DATE-TIME:20201203T171500Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-379@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Przemysław Nowak (Warsaw University of Technology\,
Faculty of Physics)\nWe study a system where a particle scatter on the pe
riodic Dirac delta potential. The problem is canonical i.e. it is consider
ed during typical quantum mechanics course. There are several approaches t
o solve the Schrodinger equation for such a systems [1] [2]. However most
of solutions rely on different matrix method. We would like to introduce n
ew\, combinatorial method by writing system of recursive equations. Based
off this solution we write transmission and reflected coefficients of a wa
ve functions of a particle\, which is the common way to describe Quantum t
unnelling. \nThe most interesting conclusion from the introduced technique
: we reveal combinatorial structure of the typical quantum mechanics probl
em and write transmission and reflected coefficients using binomial coeffi
cients as the number of combinations with repetition.\n\n[1] Fatih Erman\,
Manuel Gadella\, and Haydar Uncu. On scattering from the one dimensional
multiple dirac delta potentials. European Journal of Physics\, 39\, 01 201
8\n[2] D. Kiang. Multiple Scattering by a Dirac Comb. American Journal of
Physics\, 42:785–787\, September 1974.\n\nhttps://zakopane.if.uj.edu.pl/
event/16/contributions/379/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/379/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Numerical solution of temperature-dependent Smoluchowski equations
DTSTART;VALUE=DATE-TIME:20201203T171300Z
DTEND;VALUE=DATE-TIME:20201203T171400Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-377@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Alexander Osinsky (Skolkovo Institute of Science and
Technology)\nIn this talk\, we provide a numerical study of the recently
developed generalised temperature-dependent Smoluchowski equations. To sol
ve the new complex system\, we adapt and improve the low-rank approach of
solving large ODE systems. This allows us to quickly find approximate solu
tions for generalised systems of Smoluchowski equations even when the coll
ision kernels change during aggregation. Our results confirm the analytica
l predictions of the temperature-dependent scaling\, including analyticall
y obtained scaling parameters. We also use a special type of Monte-Carlo s
imulations (temperature-dependent Monte-Carlo) to plot a phase diagram for
different values of aggregation probability. We observe both temperature
decrease and temperature increase scaling\, as well as find more interesti
ng behaviours at small system times.\n\nhttps://zakopane.if.uj.edu.pl/even
t/16/contributions/377/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/377/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Phase transitions in the q-voter model with generalized anticonfor
mity
DTSTART;VALUE=DATE-TIME:20201203T171200Z
DTEND;VALUE=DATE-TIME:20201203T171300Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-376@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Angelika Abramiuk-Szurlej (Wroclaw University of Sci
ence and Technology)\nRecent empirical studies provide evidence that so-ca
lled social hysteresis [1] is present in animal [1\, 2\, 3] as well as in
human societies [4\, 5\, 6]\, which would suggest that (at least some) pha
se transitions observed in real social systems are discontinuous. It occur
s that discontinuous phase transitions are not that typical in models of o
pinion dynamics. Within several versions of the $q$-voter model [7]\, belo
nging to the class of the binary-state dynamics [8\, 9]\, only continuous
phase transitions has been observed\, including the original $q$-voter mod
el [10] or the $q$-voter model with anticonformity [11]. However\, the cha
nge of transition from continuous to discontinuous (for $q>5$) has been re
ported for the $q$-voter model with independence [11].\n\nIn [12] we intro
duce a $q$-voter model with generalized anticonformity. Previously it was
assumed that the size of the unanimous group of influence needed for both
conformity and anticonformity is equal [11]. We abandon this unjustified a
ssumption and introduce a generalized model\, in which the size of the inf
luence group needed for conformity $q_c$ and the size of the group needed
for anticonformity $q_a$ are independent variables and in general $q_c \\n
eq q_a$.\n\nWe consider a system of $N$ voters that form vertexes of an ar
bitrary network. Each of them is characterized by the dynamical binary var
iable $S_i(t) = \\pm 1$\, $i = 1$\, $\\ldots$\, $N$ which\, in case of soc
ial systems\, can be interpreted as an opinion on a given subject (yes/no\
, agree/disagree) at a given time $t$. In each elementary time step we ran
domly choose one agent that will reconsider its opinion. With probability
$p$ the chosen voter behaves like an anticonformist\, whereas with complem
entary probability $1 - p$ like a conformist. In any case we randomly choo
se a group of influence from the nearest neighbours of the agent without r
epetitions. The size of the group depends on the voter's response to socia
l pressure ($q_a$ for anticonformity\, $q_c$ for conformity). For $q_a = q
_c = q$ the model reduces to the original $q$-voter model with anticonform
ity introduced in [11]. If the group of influence is unanimous\, the voter
is influenced by the group and adapts to it (in case of conformity) or re
bels against it (in case of anticonformity).\n\nWe analyse the model on a
complete graph using linear stability analysis\, numerical methods and Lan
dau's theory. We calculate the analytical formulas for the lower spinodal
and the tricritical point for which the phase transition changes from cont
inuous to discontinuous. It has occurred that the generalized model displa
ys both continuous and discontinuous phase transitions depending on the si
zes of the groups of influence needed for conformity $q_c$ and anticonform
ity $q_a$. If the parameter $q_c$ is sufficiently larger than $q_a$\, the
type of the phase transition changes to discontinuous.\n\n[1] Doering\, G.
N.\, Scharf\, I.\, Moeller\, H.V.\, Pruitt\, J.N. *Social tipping points i
n animal societies in response to heat stress*. Nature Ecology and Evoluti
on\, 2(8):1298-1305\, (2018)\n[2] Beekman\, M.\, Sumpter\, D.J.T.\, Ratnie
ks\, F.L.W. *Phase transition between disordered and ordered foraging in p
haraoh's ants*. Proceedings of the National Academy of Sciences of the Uni
ted States of America\, 98(17):9703-9706\, (2001)\n[3] Pruitt\, J.N.\, Ber
dahl\, A.\, Riehl\, C.\, Pinter-Wollman\, N. and Moeller\, H.V.\, Pringle\
, E.G.\, Aplin\, L.M.\, Robinson\, E.J.H.\, Grilli\, J.\, Yeh\, P.\, Savag
e\, V.M.\, Price\, M.H.\, Garland\, J.\, Gilby\, I.C.\, Crofoot\, M.C.\, D
oering\, G.N.\, Hobson\, E.A. *Social tipping points in animal societies*.
Proceedings of the Royal Society B: Biological Sciences\, 285(1887):20181
282\, (2018)\n[4] Clark\, A.E. *Unemployment as a Social Norm: Psychologic
al Evidence from Panel Data*. Journal of Labor Economics\, 21(2):323-351\,
(2003)\n[5] Elster\, J. *A Note on Hysteresis in the Social Sciences*. Sy
nthese\, 33(2/4):371-391\, (1976)\n[6] Scheffer\, M.\, Westley\, F.\, Broc
k\, W. *Slow response of societies to new problems: Causes and costs*. Eco
systems\, 6(5):493-502\, (2003)\n[7] Castellano\, C.\, Muñoz\, M.A.\, Pas
tor-Satorras\, R. *Nonlinear q-voter model*. Physical Review E\, 80(4):041
129\, (2009)\n[8] Gleeson\, J.P. *Binary-state dynamics on complex network
s: Pair approximation and beyond*. 3(2):021004\, (2013)\n[9] Jędrzejewski
\, A.\, Sznajd-Weron\, K. *Statistical Physics Of Opinion Formation: is it
a SPOOF?* Comptes Rendus Physique\, 20(4):244-261\, (2019)\n[10] Castella
no\, C.\, Fortunato\, S.\, Loreto\, V. *Statistical physics of social dyna
mics*. Reviews of Modern Physics\, 81(2):591-646\, (2009)\n[11] Nyczka\, P
.\, Sznajd-Weron\, K.\, Cisło\, J. *Phase transitions in the q-voter mode
l with two types of stochastic driving*. 86(1):011105\, (2012)\n[12] Abram
iuk\, A.\, Pawłowski\, J.\, Sznajd-Weron\, K. *Is Independence Necessary
for a Discontinuous Phase Transition within the q-Voter Model?* Entropy\,
21:521\, (2019)\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributions/37
6/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/376/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Exploring "inverse stochastic resonance” and nonstandard stochas
tic resonance with information-theoretic tools
DTSTART;VALUE=DATE-TIME:20201203T171100Z
DTEND;VALUE=DATE-TIME:20201203T171200Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-407@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Nataniel Martinez (IFIMA-CONICET)\nSome pacemaker ne
urons show a depression of their mean firing rate for intermediate noise a
mplitudes\, which reminds the response enhancement known as “stochastic
resonance” (SR). Even though its analogy with SR goes no further\, this
phenomenon has been termed “inverse stochastic resonance” (ISR). In a
recent work\, the ISR phenomenon -as well as its close relative “nonstan
dard SR” (or more properly\, noise-induced activity amplification\, NIAA
)- have been shown to stem from the weak-noise quenching of the initial di
stribution\, in bistable regimes where the metastable state has a larger a
ttraction basin than the global minimum. To further illustrate the mechani
sm whereby the ISR and NIAA phenomena take place\, we revisit the one-vari
able model that led to that conclusion\, exploring it with information-the
oretic tools.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributions/407/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/407/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Efficiency of energy harvesting out of colored Lévy fluctuations\
, by a harmonic piezoelectric transducer
DTSTART;VALUE=DATE-TIME:20201203T171000Z
DTEND;VALUE=DATE-TIME:20201203T171100Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-358@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Martín E. Giuliano ()\nBased on studies where a lin
ear piezoelectric energy harvester is subjected to external random mechani
cal excitations modeled through Gaussian noises (white and colored)\, it w
as decided to propose a more general colored noise of the Levy α−stable
type. Analytical\, exact and approximate results and numerical results ar
e presented on the characteristics of such excitations and the electrical
power that can be extracted from them.\n\nhttps://zakopane.if.uj.edu.pl/ev
ent/16/contributions/358/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/358/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Search efficiency of (discrete) fractional Brownian motion in a ra
ndom distribution of targets
DTSTART;VALUE=DATE-TIME:20201203T170900Z
DTEND;VALUE=DATE-TIME:20201203T171000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-375@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Seyed Mohsen Jebreiil Khadem (Technische Universitä
t Berlin)\nEfficiency of search for randomly distributed targets is a prom
inent problem in many branches\nof the sciences. For the stochastic proces
s of Lévy walks\, a specific range of optimal efficiencies\nwas suggeste
d under variation of search intrinsic and extrinsic environmental paramete
rs. We study fractional Brownian motion as a search process\, which under
parameter variation\ngenerates all three basic types of diffusion\, from s
ub- to normal to superdiffusion. In contrast to Lévy\nwalks\, fractional
Brownian motion defines a Gaussian stochastic process with power law memo
ry\nyielding anti-persistent\, respectively persistent motion. Computer si
mulations of this search process\nin a uniformly random distribution of ta
rgets show that maximising search efficiencies sensitively\ndepends on the
definition of efficiency\, the variation of both intrinsic and extrinsic
parameters\, the\nperception of targets\, the type of targets\, whether to
detect only one or many of them\, and the\nchoice of boundary conditions.
We find that different search scenarios favour different modes of\nmotion
for optimising search success\, defying a universality across all search
situations. Some of our\nresults are explained by a simple analytical mode
l. Having demonstrated that search by fractional\nBrownian motion is a tru
ly complex process\, we propose an over-arching conceptual framework\nbase
d on classifying different search scenarios. This approach incorporates se
arch optimisation by\nLévy walks as a special case.\n\nhttps://zakopane.
if.uj.edu.pl/event/16/contributions/375/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/375/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Electronic relaxation in solution: Exact solution of multi-state p
roblems in time domain
DTSTART;VALUE=DATE-TIME:20201203T170800Z
DTEND;VALUE=DATE-TIME:20201203T170900Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-374@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Swati Mudra (Indian Institute of Technology Mandi\,
HP\, India)\nElectronic relaxation in solution is an interesting phenomeno
n from experimental as well as theoretical point of view. This diffusion c
ontrolled process has been theoretically modeled by using Smoluchowski equ
ation with a position dependent sink term. The problem has been solved for
different potentials and sink functions. Single state problem where Smolu
chowski equation for harmonic potential with a Dirac delta sink is the mos
t general model which has been solved analytically in Laplace domain. Due
to the complexity of equation\, there is no time domain solution have been
reported. In this work\, we will give the exact analytical solution for t
his problem in time domain. We have solved one dimensional Smoluchowski eq
uation for harmonic potential with a sink of ultra-short width. This probl
em has been solved for single state as well as two state model exactly in
time domain. We have used Green's function method to solve the equation an
d calculated survival probability. For two state model\, survival probabil
ity for both the states have been calculated explicitly. We have developed
a general method to solve single state as well as coupled two state model
which can be used to solve many similar problems.\n\nhttps://zakopane.if.
uj.edu.pl/event/16/contributions/374/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/374/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Energetics of critical oscillators in active bacterial baths
DTSTART;VALUE=DATE-TIME:20201203T170700Z
DTEND;VALUE=DATE-TIME:20201203T170800Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-373@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Ashwin Gopal (University of Luxembourg)\nWe investig
ate the nonequilibrium energetics near a critical point of a non-linear d
riven oscillator immersed in an active bacterial bath. At the critical poi
nt\, we reveal a scaling exponent of the average power $\\langle\\dot{W}\
\rangle\\sim (D_{\\rm a}/\\tau)^{1/4}$ where $D_{\\rm a}$ is the effective
diffusivity and $\\tau$ the correlation time of the bacterial bath descr
ibed by Gaussian colored noise. Other features that we investigate are the
average stationary power and the variance of the work both below and abov
e the saddle-node bifurcation. Above the bifurcation\, the average power
attains an optimal\, minimum value for finite $\\tau$ that is below its z
ero-temperature limit. Furthermore\, we reveal a finite-time uncertainty r
elation for active matter\, which leads to values of the Fano factor of t
he work that can be below $2k_{\\rm B}T_{\\rm eff}$\, with $T_{\\rm eff}$
the effective temperature of the oscillator in the bacterial bath. We anal
yze different Markovian approximations to describe the nonequilibrium stat
ionary state of the system. Finally\, we illustrate our results in the exp
erimental context by considering the example of driven colloidal particles
in periodic optical potentials within a E. Coli bacterial bath.\n\nhttps:
//zakopane.if.uj.edu.pl/event/16/contributions/373/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/373/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Temperature-dependent Smoluchowski equations
DTSTART;VALUE=DATE-TIME:20201203T170600Z
DTEND;VALUE=DATE-TIME:20201203T170700Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-378@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Nikolai Brilliantov (Skolkovo Institute of Science a
nd Technology)\nWe report a new class of Smoluchowski-like equations for b
allistically aggregating particles in a space-uniform system. They natural
ly emerge when the derivation of the aggregation equations is performed st
arting from the Boltzmann kinetic equation for the mass-velocity distribut
ion functions [1]. Then the system of equations for the zero-order moments
of the distribution functions – the concentrations of aggregates of dif
ferent size\, corresponds to the conventional Smoluchowski equations. The
aggregation rate coefficients of these equations depend on the second mome
nts of the distribution function – partial temperatures of the aggregate
s. In this way\, we obtain two coupled systems of equations – for the co
ncentrations and temperatures [1]. We show that\, depending on the aggrega
tion probability\, these equations provide two main types of scaling. The
first one\, when all collisions are aggregative leads to Smoluchowski-type
evolution with a gradual decrease in temperature. The second one\, when o
nly a small fraction of collisions are aggregative\, results in a stunning
effect of the aggregation with temperature growth. We show that the tempe
rature increase may be stable and perpetual until the system remains large
enough for the notion of the temperature to persist. We also estimate the
system parameters (restitution coefficient\, aggregation probability)\, w
hich can lead to this type of scaling. The theoretical results are confirm
ed by the numerical simulations.\n\n[1] N. Brilliantov\, T. Poeschel\, and
A. Formella\, Increasing temperature of cooling granular gases\, Nature C
ommunications\, 9 (2018) 797.\n\nhttps://zakopane.if.uj.edu.pl/event/16
/contributions/378/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/378/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Photoluminescence of Complex Systems
DTSTART;VALUE=DATE-TIME:20201203T170500Z
DTEND;VALUE=DATE-TIME:20201203T170600Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-380@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Ambra Lattanzi (Institute of Nuclear Physics IFJ-PAN
\, Krakòw\, Poland - ENEA FSN-FUSPHYS-TSM\, Frascati (Rome)\, Italy)\nThe
photoluminescence degradation of the thermally evaporated Alq3 thin films
can be described by a four components model based on the Kohlrausch-Willi
ams-Watt (KWW) function. This model improved the agreement between experim
ental data and the theoretical fit with respect to the four components mod
el based on “pure” exponential functions. In fact\, the negative bump
in PL intensity decay observed in the reference not-annealed sample is per
fectly fitted\, and the last part of the time resolved spectroscopy improv
ed its adherence to experimental data both in annealed and not-annealed sa
mples.\nA material frame of reference has been introduced in order to inve
stigate the physical nature of the KWW function in relaxation processes an
d at the same time\, explain the peculiar experimental features emerged in
the time-spectral PL behaviour. The introduction of a nonlinear time vari
able\, named material clock or material time\, overcomes the difficulties
carried by the anomalous behaviour considering the process from a bare poi
nt of view: the relaxation behaves ideally whereas the material frame of r
eference is going to be stretched or compressed. This allows to model the
PL degradation dynamics as a damped harmonic oscillator. Once the physics
has been understood\, it is possible to restore the laboratory frame of re
ference and define the reduced mass\, a time-depending function that unloc
ks the physical meaning of the experimental peculiarities observed in the
PL emission. \nThe results are framed in the context of physical-chemical
reactions in order to emphasize how the KWW function is a sum of sub-proc
esses. The physical meaning of these sub-processes can be related to inter
nal and environmental agents interactions under defined physical condition
s. These insights highlight the usefulness of the proper mathematical proc
edures and properties\, such as the monotonicity and the complete monotoni
city\, for investigating the PL emission of this organometallic molecule.
Moreover\, this method is also promising for describing the photoluminesce
nt processes of similar organic molecules both for basic research and opto
electronic applications.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contrib
utions/380/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/380/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Exploring shape space for densest random sequential adsorption pac
king
DTSTART;VALUE=DATE-TIME:20201203T170300Z
DTEND;VALUE=DATE-TIME:20201203T170400Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-415@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Konrad Kozubek (Institute of Theoretical Physics\, J
agiellonian University)\nRandom sequential adsorption of various shapes bu
ilt of disks is studied to determine the shape\, which follows to densest
random packing. Using the evolutionary algorithm to sample the space of s
hapes\, we found that independently of the number of used disks\, the opti
mal shape tends to a triangle with rounded corners. Thus\, we run the sam
e algorithm to study packings built of rounded polygons. Both these appro
aches indicate that the shape building the densest RSA packings is the rou
nded triangle\, for which the packing fraction is 0.600608±0.000017\, whi
ch is the highest known value so far.\n\nhttps://zakopane.if.uj.edu.pl/eve
nt/16/contributions/415/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/415/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kramers-like problem for underdamped Levy flights
DTSTART;VALUE=DATE-TIME:20201203T170200Z
DTEND;VALUE=DATE-TIME:20201203T170300Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-416@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Karol Capała (Institute of Theoretical Physics\, Ja
giellonian University)\nThe noise driven motion in a bistable potential ac
ts as the archetypal model of various physical phenomena. In the weak noi
se limit\, for the overdamped particle driven by a non-equilibrium\, $\\al
pha$-stable noise the ratio of forward and backward transition rates depe
nds only on the width of the potential barrier separating both minima. The
poster presents analytical and numerical results showing that in the regi
me of full dynamics the ratio of transition rates depends both on widths a
nd heights of the potential barrier separating minima of the double-well
potential.\n\n\nK. Capała and B. Dybiec\, *Underdamped\, anomalous kineti
cs in double-well potentials*\, Phys. Rev. E **102**\, 052123 (2020).\n\nh
ttps://zakopane.if.uj.edu.pl/event/16/contributions/416/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/416/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Statistical physics of inhomogeneous transport equations: first pa
ssage to the space-dependent diffusion
DTSTART;VALUE=DATE-TIME:20201203T170100Z
DTEND;VALUE=DATE-TIME:20201203T170200Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-409@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Roman Belousov (The Abdus Salam International Centre
for Theoretical Physics)\nAs the science and modern technologies are seiz
ing the realm of nanoscale systems\, characterization of composite materia
ls with solid-fluid and fluid-fluid interfaces has become a problem of bro
ad interdisciplinary interest. Properties of such complex systems\, which
vary in space over microscopic scales\, shape important processes in engin
eering and biology. Estimation of the inhomogeneous—space-dependent—tr
ansport coefficients that characterize these processes\, e.g. the diffusio
n coefficient or the heat conductivity\, is however a challenging task. Mo
reover\, two alternative formulations of the inhomogeneous transport equat
ions exist in the literature. Using the theory of statistical physics\, in
my talk I will show that the two formulations\, often regarded as distinc
t models\, are in fact equivalent. In particular\, one of them convenientl
y links the mass diffusion equation with statistics of molecules' first-pa
ssage events\, which provide an efficient inference technique for the spac
e-dependent diffusion coefficient.\n\nhttps://zakopane.if.uj.edu.pl/event/
16/contributions/409/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/409/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Detection of interaction and energy exchange with invisible partne
rs in localized Brownian dumbbells
DTSTART;VALUE=DATE-TIME:20201203T170000Z
DTEND;VALUE=DATE-TIME:20201203T170100Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-404@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Alexander S. Serov (Decision and Bayesian Computatio
n\, Department of Computational Biology\, Department of Neurosciences\, CN
RS USR 3756\, CNRS UMR 3571\, Institut Pasteur\, 25 rue du Docteur Roux\,
Paris\, 75015\, France)\nWhen recording trajectories of biomolecules in cr
owded media\, a question of fundamental interest is whether a tracked mole
cule interacts with other molecules or structures invisible to the observe
r. One also wants to know whether energy exchange occurs during such inter
actions since out-of-equilibrium interactions can be a sign of a specific
biological function. Addressing these questions using recorded single-part
icle trajectories is\, in general\, an ill-posed problem. In this work\, w
e demonstrate how and when possible interactions and energy transfer betwe
en the particles can be detected in an idealized system consisting of two
linked localized Brownian particles\, where only one of the two trajectori
es is recorded.\n\nTo these means\, we designed a Bayesian test for whethe
r the observed trajectory corresponds to a single particle or 2 linked par
ticles. The test leverages Bayesian statistics to compare the evidence for
that the input trajectory’s power spectrum is generated by an independe
nt particle or a particle with a partner. Extensive numerical simulations
allowed us to establish parameter regions\, within which such partner dete
ction is possible. As expected\, the test is most sensitive to the link st
rength and the ratio of particle diffusivities. As a byproduct\, we also o
btained estimates of the localization strength and diffusivities of both p
articles.\n\nFor systems where a difference in diffusivities can be interp
reted as a difference in local temperatures\, we further extended our appr
oach to determine whether the physical system is out of equilibrium. Using
numerical simulations\, we identified the parameter range where the disti
nction can be reliably made from recorded data.\n\nDespite the simplicity
of the model\, the application of the method to real experimental trajecto
ries may help identify the presence of an interaction partner\, the intera
ction direction\, and the presence of potential energy fluxes.\n\nhttps://
zakopane.if.uj.edu.pl/event/16/contributions/404/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/404/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Opening
DTSTART;VALUE=DATE-TIME:20201203T075000Z
DTEND;VALUE=DATE-TIME:20201203T080000Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-411@zakopane.if.uj.edu.pl
DESCRIPTION:https://zakopane.if.uj.edu.pl/event/16/contributions/411/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/411/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The effect of substrate roughness on random sequential adsorption
packing properties
DTSTART;VALUE=DATE-TIME:20201203T172600Z
DTEND;VALUE=DATE-TIME:20201203T172700Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-424@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Piotr Kubala (Institute of Theoretical Physics\, Jag
iellonian University)\nAdsorption on smooth and atomistically flat surface
is well understood\, while still very few works concern adsorption on rou
gh and heterogeneous surfaces. In this study\, we investigate the properti
es of packings of balls obtained via random sequential adsorption (RSA) on
a sinusoidal substrate. Our main goal is to observe surface inhomogeneiti
es on a scale smaller than particles' size. We study how various character
istics\, such as packing fraction\, packing growth kinetics\, available su
rface function and 2-particle density correlation function depend on the w
avenumber and the amplitude of a sine-wave-shaped surface. These quantitie
s indeed allow us to discern very minute surface impurities from the packi
ng alone.\n\nhttps://zakopane.if.uj.edu.pl/event/16/contributions/424/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/424/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nanoscale Lubrication in Model Biosystems as Rationalized in Terms
of Fractons and Spectral-Mechanical Properties of Networked Biopolymers i
n Solutions
DTSTART;VALUE=DATE-TIME:20201203T172600Z
DTEND;VALUE=DATE-TIME:20201203T172700Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-423@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: ADAM GADOMSKI (UTP UNIVERSITY OF SCIENCE &\; TECH
NOLOGY BYDGOSZCZ\, POLAND)\nA concept of a biopolimer network immersed wit
hin an aqueous solution as addressed in terms of flexibility vs. mechanic
al stability criterion has been proposed. It is based on a transmission of
correlated wave of (hydrogen) ions emerging from breaking in a massive wa
y the hydrogen bonds between the biopolymers\, such as hyaluronan\, and th
eir non-ideal aqueous solution’s surroundings. \nBased on the argumentat
ion presented in a paper by Reuveni et al. [1] it has been demonstrated th
at there exists a clear connection between the ln(N) (a natural logarithm
of the biopolymer length N) and an inverse of a difference between two maj
or contributions of this Landau-Peierls instability type paradigm. Providi
ng that the so-called Alexander-Orbach conjecture for the oscillating biop
olymeric system applies [2\,3] one of the contributions is of mechanical n
ature\, with an exponent g represented by 1/(2-3g) whereas the other appea
rs to be a surface-to-volume characteristic exponent\, attaining preferent
ially a value of ca. 2/3 for a three-dimensional adjacent (articulating)
space. \nIt has been shown in a numerical way that for N of the order of m
ilion(s) biopolymer’s residues\, for example for hyaluronan equivalent t
o its molecular weight of 10^6-6x10^6 Daltons\, a measure of the best visc
oelastic efficiency for the hyaluronan\, there exists an equality ln(N) =
b/[1/(2-3g) – 2/3] that\, for example\, for N=10^6 gives the value of me
chanical exponent g close to 1/3\, yielding according to [3\,4]\, an excel
lent passage of the (hydrogen) ions’ wave derived from a breakage of the
adjacent hydrogen bonds in the biopolymer-solution system of interest\, p
rovided that the constant b\, according to [1]\, can be taken at b=4.5. (I
n general\, for the exponent g > 1/6 holds.) The first results seem to be
promising when thoroughly rationalizing nanoscale friction-lubrication pro
perties of biopolymer-solution articulating/confined subspaces exposed to
very small nano-Newton loading conditions. For another thermomechanical sc
enario describing phase-transition and relaxation kinetics of a biopolymer
ic system\, see [5]. \nReferences\n[1] S. Reuveni et al. PRL 100\, 208101
(2008). \n[2] S. Alexander\, R. Orbach J. Physique-LETTRES 43\, L-625 (19
82). \n[3] A. Gadomski et al. Tribol. Lett. 30\, 83 (2008). \n[4] A. Gadom
ski et al. Mathematical Biosciences 244\, 188 (2013) . \n[5] A. Gadomski\,
J. Łuczka\, Acta Phys. Pol. B 28\, 1827 (1997)\; A. Gadomski et al. Euro
p. Phys. J. B 91\, 237 (2018). \n\nEmail address: agad@utp.edu.pl (to whom
the correspondence can be addressed).\n\nhttps://zakopane.if.uj.edu.pl/ev
ent/16/contributions/423/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/423/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Express your scientific track record in just three numbers
DTSTART;VALUE=DATE-TIME:20201203T172500Z
DTEND;VALUE=DATE-TIME:20201203T172600Z
DTSTAMP;VALUE=DATE-TIME:20210805T115300Z
UID:indico-contribution-16-422@zakopane.if.uj.edu.pl
DESCRIPTION:Speakers: Grzegorz Siudem (Warsaw University of Technology)\nT
he growing popularity of bibliometric indexes goes hand in hand with their
critique by those who claim that scientist’s impact cannot be reduced t
o a single number. Some even believe that such a complex reality fails to
submit to any quantitative description. We argue that neither of the two c
ontroversial extremes is true. With our new agent-based model (doi.org/10.
1073/pnas.2001064117) we can describe the emergence of citation curves ve
ry accurately. \n\nIn the model we assumed that some citations are distri
buted according to the rich get richer rule while some others are allocate
d totally at random. This yields a very accurate model that is governed by
merely three easily interpretable parameters: productivity\, total impact
\, and rho\, which measures preferential vs. random rules ratio..\n\nhttps
://zakopane.if.uj.edu.pl/event/16/contributions/422/
LOCATION:
URL:https://zakopane.if.uj.edu.pl/event/16/contributions/422/
END:VEVENT
END:VCALENDAR