Phase transitions for the Widom--Rowlinson model in random environments
Benedikt Jahnel, Daniel Kamecke
TL;DR
This work extends the phase-transition theory for the continuum two-colored Widom--Rowlinson model to inhomogeneous and random environments. By leveraging a random-cluster representation and FKG domination, the authors relate non-uniqueness of infinite-volume Gibbs measures to a-percolation of the underlying point process, proving almost-sure non-uniqueness for Cox processes with stationary intensity distributions in suitable regimes. The results cover both fixed inhomogeneous environments and random environments, yielding explicit percolation-based criteria (via a dimension-dependent constant $\tau$) that guarantee multiple Gibbs measures and hence a phase transition. The approach also encompasses stabilizing, asymptotically essentially connected random environments, ensuring percolation and almost-sure non-uniqueness for a broad class of Cox point processes, with concrete examples including absolutely continuous and singular environments such as Poisson–Voronoi tessellations and Poisson–Manhattan grids. The findings connect continuum Gibbs theory with percolation and random-field analogies, providing robust tools for understanding phase behavior in spatially heterogeneous media.
Abstract
We establish non-uniqueness regimes for the infinite-volume two-colored Widom--Rowlinson model based on inhomogeneous Poisson point processes with locally finite intensity measures featuring percolation. As an application, we provide almost-sure phase-transition results for the Widom--Rowlinson model based on translation-invariant and ergodic Cox point processes with stabilizing and non-stabilizing directing measures.
