Low temperature analysis of two dimensional Fermi systems with symmetric Fermi surface

TL;DR

This paper proves the convergence of a Renormalization Group-based perturbative expansion for weakly interacting 2D fermion systems with symmetric Fermi surfaces at very low temperatures, near superconductivity onset.

Contribution

It provides a rigorous proof of convergence for the perturbative expansion in two-dimensional fermion systems at low temperatures, advancing understanding of superconductivity onset.

Findings

Convergence of perturbative expansion established

Analysis valid up to exponentially small temperatures

Results applicable near superconductivity transition

Abstract

We prove the convergence of the perturbative expansion, based on Renormalization Group, of the two point Schwinger function of a system of weakly interacting fermions in d=2, with symmetric Fermi surface and up to exponentially small temperatures, close to the expected onset of superconductivity