Critical exponents of the Gross-Neveu model from the effective average action

TL;DR

This paper uses a non-perturbative approach to calculate critical exponents of the Gross-Neveu model in three dimensions, confirming its universality class with the Neveu-Yukawa model.

Contribution

It provides the first comprehensive non-perturbative calculation of critical exponents for various N in the Gross-Neveu model using the effective average action.

Findings

Critical exponents are computed for different N values.

The Gross-Neveu and Neveu-Yukawa models are confirmed to share the same universality class.

The approach validates the use of the effective average action for phase transition analysis.

Abstract

The phase transition of the Gross-Neveu model with N fermions is investigated by means of a non-perturbative evolution equation for the scale dependence of the effective average action. The critical exponents and scaling amplitudes are calculated for various values of N in d=3. It is also explicitely verified that the Neveu-Yukawa model belongs to the same universality class as the Gross-Neveu model.