Phase Transitions and Decision Making

Abstract

In this chapter we consider a simple model of interacting agents considering a binary question, asked to reply “yes” or "not" to the question. The agents are described in terms of spin variables, and they interact according to a mean field Heisenberg model. We discuss under which conditions the agents can come out with a common choice. This is made using, in a social context, the notion of KMS-states and phase transitions, used in quantum statistical mechanics and in algebras of bounded operators