Identity of the universal repulsive-core singularity with Yang-Lee edge criticality

TL;DR

This paper analytically demonstrates that the universal repulsive-core singularity in fluid models is equivalent to the Yang-Lee edge criticality, linking two important phenomena through a field-theory approach.

Contribution

It provides the first general analytic proof that the repulsive-core singularity belongs to the Yang-Lee edge universality class.

Findings

Repulsive-core singularity is universal and matches Yang-Lee edge criticality.

Field-theory approach effectively separates repulsive and attractive interactions.

Analytic demonstration confirms numerical suggestions of the universality class.

Abstract

Lattice and continuum fluid models with repulsive-core interactions typically display a dominant, critical-type singularity on the real, negative activity axis. Lai and Fisher recently suggested, mainly on numerical grounds, that this repulsive-core singularity is universal and in the same class as the Yang-Lee edge singularities, which arise above criticality at complex activities with positive real part. A general analytic demonstration of this identification is presented here using a field-theory approach with separate representation of the repulsive and attractive parts of the pair interactions.