Non-Convex Multipartite Ferromagnets

TL;DR

This paper analyzes a multipartite ferromagnetic model without self-interactions, deriving its free energy, examining phase transitions under various conditions, and studying magnetization fluctuations especially in the bipartite case.

Contribution

It introduces a novel ferromagnetic model lacking self-interactions and provides a comprehensive analysis of its free energy and phase transition behavior.

Findings

Derived the free energy for the model.

Identified phase transition points for zero external fields.

Analyzed magnetization fluctuations in the bipartite case.

Abstract

We investigate a multipartite ferromagnetic model without self-interactions between spins of the same party, so that the Hamiltonian is not a definite quadratic form of the magnetisations. We find the free energy and study the phase transition for all zero external fields. Moreover in the bipartite case we analyse the fluctuations of the rescaled magnetisations, below and at the critical point, and we study the phase transitions with non zero magnetic fields.