Non-perturbative construction of counterterms for 2PI-approximation

TL;DR

This paper introduces a non-perturbative method for calculating counterterms in 2PI-approximations, applicable to scalar fields and extendable to theories with global symmetries.

Contribution

It provides a concise, generalizable approach for renormalizing 2PI actions non-perturbatively, up to lambda^2 order in skeleton truncation.

Findings

Method successfully renormalizes 2PI actions for scalar fields.

Applicable to theories with arbitrary global symmetry.

Eases non-perturbative calculations in quantum field theory.

Abstract

A concise method is presented for the non-perturbative computation of the counterterms renormalising 2PI-actions. The procedure is presented for a real scalar field up to lambda^2 order in the skeleton truncation of Gamma_2PI with respect to the self-coupling, and in a constant symmetry breaking background. The method is easily generalizable to field theories with arbitrary global symmetry.