2026/07/22 by Felipe Penafiel, Kádmo Laxa
Mathematics · #math.PR
We consider a stochastic opinion dynamics model on a fully connected social network with N actors interacting by expressing opinions from a set of M opinions. At any time t≥ 0, each actor is associated to an M-tuple representing the social pressure exerted on this actor for each opinion. The evolution of the matrix containing the social pressure of all actors for all opinions is a Markov jump process. Each actor tends to express opinions according to their social pressure vector and this tendency is modulated by a polarization coefficient. When an actor expresses an opinion o, its social pressure for all opinions is reset to zero, while for other actors the social pressure for o increases by 1 and the social pressure for other opinions decreases by 1/(M-1). In this setting, we prove fast consensus formation, existence of a unique invariant measure and metastability in a highly polarized network. Moreover, by considering a communication bias parameter, the system exhibits a phase transition described as follows. With a negative communication bias parameter, all actors except one stop expressing in a finite time almost surely. Otherwise, no actor stops expressing opinions.