Uniqueness for DLR equations of ${\mathsf{Sine}}_{\beta }$

Abstract

We prove that, for all $\beta >0$, the Dobrushin-Lanford-Ruelle (DLR) equations for the unit-intensity ${\mathsf{Sine}}_{\beta }$ point process have a unique stationary solution under a particular finite electric energy condition. Uniqueness fails if this condition is dropped. This answers a question of Dereudre-Hardy-Leblé-Maïda and gives a canonical statistical physics characterisation of ${\mathsf{Sine}}_{\beta }$. The main technical ingredient is a relative entropy estimate which allows us to compare the conditional distribution in a finite box of a DLR solution to a corresponding circular $\beta$ ensemble.