Eur. Phys. J. B 79, 99-106 (2011)
https://doi.org/10.1140/epjb/e2010-10568-y

Dynamical phase transitions in Hegselmann-Krause model of opinion dynamics and consensus

¹ Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Praha, Czech Republic
² Center for Theoretical Study, Charles University in Prague, Academy of Sciences of the Czech Republic, Jilská 1, 11000 Praha, Czech Republic

Corresponding author: ^a slanina@fzu.cz

Received: 22 July 2010
Revised: 19 November 2010
Published online: 23 December 2010

Abstract

The dynamics of the model of agents with limited confidence introduced by Hegselmann and Krause exhibits multiple well-separated regimes characterised by the number of distinct clusters in the stationary state. We present indications that there are genuine dynamical phase transitions between these regimes. The main indicator is the divergence of the average evolution time required to reach the stationary state. The slowdown close to the transition is connected with the emergence of the groups of mediator agents which are very small but have decisive role in the process of social convergence. More detailed study shows that the histogram of the evolution times is composed of several peaks. These peaks are unambiguously interpreted as corresponding to mediator groups consisting of one, two, three etc. agents. Detailed study reveals that each transition possesses also an internal fine structure.