3-4 December 2020
Europe/Warsaw timezone

The q-voter model with attractive and repulsive interactions and independence on random graphs

4 Dec 2020, 12:20
20m
20 minute talk S5

Speaker

Dr. Andrzej Krawiecki (Faculty of Physics, Warsaw University of Technology)

Description

The $q$-voter model with both attractive (roughly speaking, ferromagnetic-like) and repulsive (antiferromagnetic-like) interactions on random graphs is investigated. In this model the agent, represented 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 $q$ randomly chosen neighbors and with probability $p$ acts independently and changes opinion randomly. In the former case the agent changes opinion if opinions of all selected neighbors interacting with him/her attractively via the attached edges of the graph ("friends") are opposite and simultaneously opinions of all selected neighbors interacting with him/her repulsively ("disliked persons") are the same as the agent's one. The parameter $p$ measures 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 approximation taking into account presence of the repulsive interactions predicts quantitatively well results of Monte Carlo simulations of the model in a broad range of parameters.

Primary author

Dr. Andrzej Krawiecki (Faculty of Physics, Warsaw University of Technology)

Presentation Materials

There are no materials yet.
Your browser is out of date!

Update your browser to view this website correctly. Update my browser now

×