The Gross-Neveu Model from String Theory

TL;DR

This paper models (1+1)-dimensional chiral fermions using intersecting D-branes in string theory, revealing how chiral symmetry breaking and restoration occur at different couplings and temperatures, with phase transition characteristics changing accordingly.

Contribution

It connects the Gross-Neveu model to string theory via D-brane configurations, providing a dual description at strong coupling.

Findings

Chiral symmetry is broken at zero temperature.

Symmetry is restored above a critical temperature T_c.

Phase transition changes from first order at strong coupling to second order at weak coupling.

Abstract

We study an intersecting D-brane model which at low energies describes (1+1)-dimensional chiral fermions localized at defects on a stack of N_c D4-branes. Fermions at different defects interact via exchange of massless (4+1)-dimensional fields. At weak coupling this interaction gives rise to the Gross-Neveu (GN) model and can be studied using field theoretic techniques. At strong coupling one can describe the system in terms of probe branes propagating in a curved background in string theory. The chiral symmetry is dynamically broken at zero temperature and is restored above a critical temperature T_c which depends on the coupling. The phase transition at T_c is first order at strong coupling and second order at weak coupling.