Chiral symmetry breaking in d=3 NJL model in external gravitational and magnetic fields

TL;DR

This paper explores how external gravitational and magnetic fields influence chiral symmetry breaking in a 3D NJL model, revealing conditions where symmetry can be broken or restored.

Contribution

It provides a detailed analysis of chiral symmetry behavior in curved spacetime with magnetic fields using the 1/N-expansion and linear curvature approximation.

Findings

Chiral symmetry can be broken by external magnetic and gravitational fields.

Under certain conditions, gravitational fields can restore chiral symmetry.

The magnetic field's effect is exactly treated, revealing complex interplay with gravity.

Abstract

The phase structure of $d=3$ Nambu-Jona-Lasinio model in curved spacetime with magnetic field is investigated in the leading order of the $1/N$-expansion and in linear curvature approximation (an external magnetic field is treated exactly). The possibility of the chiral symmetry breaking under the combined action of the external gravitational and magnetic fields is shown explicitly. At some circumstances the chiral symmetry may be restored due to the compensation of the magnetic field by the gravitational field.