Finite Volume Chiral Partition Functions and the Replica Method

TL;DR

This paper proves the equivalence of supersymmetric and replica methods in finite volume chiral perturbation theory for Dyson indices =1 and 4, deriving universal equations and corrections relevant for understanding symmetry breaking.

Contribution

It introduces a universal differential equation for finite volume partition functions and demonstrates the equivalence of two key methods in specific symmetry classes.

Findings

Derived a universal differential equation for the partition function.

Established the equivalence of supersymmetric and replica methods.

Calculated the first finite volume correction to the chiral condensate.

Abstract

In the framework of chiral perturbation theory we demonstrate the equivalence of the supersymmetric and the replica methods in the symmetry breaking classes of Dyson indices \beta=1 and \beta=4. Schwinger-Dyson equations are used to derive a universal differential equation for the finite volume partition function in sectors of fixed topological charge, \nu. All dependence on the symmetry breaking class enters through the Dyson index \beta. We utilize this differential equation to obtain Virasoro constraints in the small mass expansion for all \beta and in the large mass expansion for \beta=2 with arbitrary \nu. Using quenched chiral perturbation theory we calculate the first finite volume correction to the chiral condensate demonstrating how, for all \betathere exists a region in which the two expansion schemes of quenched finite volume chiral perturbation theory overlap.