Sep 2 – 7, 2018
Europe/Warsaw timezone

Anomalous diffusion, ergodicity, ageing, and non-gaussianity

Sep 4, 2018, 9:00 AM


Prof. Ralf Metzler (University of Potsdam)


A surging amount of experimental and simulations studies reveals persistent anomalous diffusion in the membranes and volume of living biological cells as well as other complex fluids [1]. This anomalous diffusion is observed for micron-sized objects down to labelled single molecules such as green fluorescent proteins [2]. In this talk I will present results from large scale computer simulations and stochastic analysis of the motion of lipids and embedded proteins in lipid bilayer model membranes [3], indicating that increased disorder leads to longer and longer lasting anomalous diffusion. In particular, the motion of lipids and proteins can become non-Gaussian [3]. In the membranes of living cells anomalous diffusion of embedded protein channels can last over several hundreds of seconds [4]. Anomalous diffusion inside the volume of cells will be discussed, as well. In particular, the emergence of non-Gaussian diffusion patterns for both Fickian and non-Fickian diffusion will be addressed within the framework of diffusing diffusivities [5]. The observed stochastic dynamics may be ergodic or not, depending on the exact physical mechanisms governing the motion of the test particle. The talk will discuss how non-ergodic behaviour needs to be taken into account when interpreting data from stochastic systems. In addition effects of ageing will be explained [6]. [1] F. Hofling and T. Franosch, Rep Progr Phys 76, 046602 (2013); K. Noerregaard, R. Metzler, C. M. Ritter, K. Berg-Soerensen, and L. B. Oddershede, Chem. Rev. 117, 4342 (2017). [2] C Di Rienzo, V Piazza, E Gratton, F Beltram, and F Cardarelli, Nature Comm 5, 5891 (2014). [3] J-H Jeon, HM-S Monne, M Javanainen, and R Metzler, Phys Rev Lett 109, 188103 (2012); J-H Jeon, M Javanainen, H Martinez-Seara, R Metzler, and I Vattulainen, Phys Rev X 6, 021006 (2016). [4] AV Weigel, B Simon, MM Tamkun, and D Krapf, Proc Natl Acad Sci USA 108, 6438 (2011). [5] AV Chechkin, F Seno, R Metzler, and IM Sokolov, Phys Rev X 7, 021002 (2017); TJ Lampo, S Stylianidou, MP Backlund, PA Wiggins, AJ Spakowitz, Biophys J 112, 532 (2017). [6] R Metzler, J-H Jeon, AG Cherstvy, E Barkai, Phys Chem Chem Phys 16 24128 (2014); JHP Schulz, E Barkai, R Metzler, Phys Rev X 4, 011028 (2014).

Primary author

Prof. Ralf Metzler (University of Potsdam)

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