Liquid-Gas phase transition for Gibbs point process with Quermass interaction
David Dereudre, Christopher Renaud-Chan
TL;DR
The paper addresses liquid-gas type phase transitions for a continuum Gibbs point process with Quermass interaction by translating the PSZ contour method to a saturation-enabled continuum setting. The authors construct a rigorous polymer/cluster expansion around coarse-grained states, establishing a Peierls-type energy bound and proving the existence of two distinct infinite-volume Gibbs measures at a critical activity $z_β^c$ when $\beta$ is large. The main contributions are the adaptation of PSZ theory to continuous systems with halo-based Minkowski functionals, the demonstration of non-differentiability of the pressure at the transition, and the precise control of truncated weights leading to a first-order transition without invoking spins. This advances understanding of phase structure in geometric continuum models and provides a robust framework for other saturated-interaction systems.
Abstract
We prove the existence of a liquid-gas phase transition for continuous Gibbs point process in $\mathbb{R}^d$ with Quermass interaction. The Hamiltonian we consider is a linear combination of the volume $\mathcal{V}$, the surface measure $\mathcal{S}$ and the Euler-Poincaré characteristic $χ$ of a halo of particles (i.e. an union of balls centred at the positions of particles). We show the non-uniqueness of infinite volume Gibbs measures for special values of activity and temperature, provided that the temperature is low enough. Moreover we show the non-differentiability of the pressure at these critical points. Our main tool is an adaptation of the Pirogov-Sinaï-Zahradnik theory for continuous systems with interaction exhibiting a saturation property.
