Social Influence of Competing Groups and Leaders in Opinion Dynamics

Publication history: Accepted - 11 September 2020; Published online - 19 September 2020.This paper explores the infuence of two competing stubborn agent groups on the opinion dynamics of normal agents. Computer simulations are used to investigate the parameter space systematically in order to determine the impact of group size and extremeness on the dynamics and identify optimal strategies for maximizing numbers of followers and social infuence. Results show that (a) there are many cases where a group that is neither too large nor too small and neither too extreme nor too central achieves the best outcome, (b) stubborn groups can have a moderating, rather than polarizing, efect on the society in a range of circumstances, and (c) small changes in parameters can lead to transitions from a state where one stubborn group attracts all the normal agents to a state where the other group does so. We also explore how these fndings can be interpreted in terms of opinion leaders, truth, and campaign

Opinion dynamics of social learning with a conflicting source

Publication history: Received in revised form - 17 September 2020; Published online - 27 October 2020.The way in which agents are influenced by the truth and/or a conflicting source can have a significant effect on the extent to which social learning is successful. We investigate these influences via several variations of the Hegselmann–Krause model of opinion dynamics. First, we compare two ways of modelling the influence of truth in the absence of a conflicting source and find that in a model where access to the truth is more restricted, increasing the proportion of truth seekers in the society has little effect on convergence to the truth. Second, we investigate the same models of truth in the presence of a conflicting source, which could represent the opinions of a radical group, opinion leader or media source. The results show that a consensus on the truth can be reached in certain cases in both models, but also that in a wide range of cases both models give rise to the same partition of the society into truth seekers and non-truth seekers

A simple model for DNA denaturation

Following Poland and Scheraga, we consider a simplified model for the denaturation transition of DNA. The two strands are modeled as interacting polymer chains. The attractive interactions, which mimic the pairing between the four bases, are reduced to a single short range binding term. Furthermore, base-pair misalignments are forbidden, implying that this binding term exists only for corresponding (same curvilinear abscissae) monomers of the two chains. We take into account the excluded volume repulsion between monomers of the two chains, but neglect intra-chain repulsion. We find that the excluded volume term generates an effective repulsive interaction between the chains, which decays as $1/r^{d-2}$. Due to this long-range repulsion between the chains, the denaturation transition is first order in any dimension, in agreement with previous studies.Comment: 10 page