Analytic perturbation theory versus 1/N expansion in the Gross-Neveu model

TL;DR

This paper compares the 1/N expansion and analytic perturbation theory in the 2D Gross-Neveu model, finding a surprising agreement at leading order between these two different methods.

Contribution

It demonstrates that analytic perturbation theory can produce results consistent with the 1/N expansion in the Gross-Neveu model at leading order.

Findings

Agreement between methods at leading order

Validation of analytic perturbation theory in this context

Potential for alternative approaches in similar models

Abstract

The 1/N expansion can be successfully used to calculate the Green functions of the two-dimensional O(2N) Gross - Neveu model. In parallel, the methods of analytic perturbation theory are also applied. Comparing the results of these two calculations at leading order, we report on the surprising agreement between them.