Comment on ``On loss of quantum coherence in an interacting Fermi gas'' (cond-mat/9810297)

TL;DR

This paper critiques a recent claim that corrected a previous analysis of quantum coherence loss in an interacting Fermi gas, demonstrating that the critique was based on mathematically flawed and physically meaningless procedures.

Contribution

It clarifies that the previous critique was founded on incorrect Gaussian path integral calculations, reaffirming the validity of the original analysis.

Findings

The critique by Eriksen and Hedegard is mathematically incorrect.

Their analysis is based on physically meaningless procedures.

The original analysis remains valid despite the critique.

Abstract

In a recent paper \cite{EH} Eriksen and Hedegard (EH) claimed that they ``clarified'' our path integral calculation \cite{GZ1} and found an error in our analysis. Here we will demonstrate that this claim is based on mathematically incorrect and physically meaningless procedure invented by the authors \cite{EH}. The main problem in the EH analysis is due to their erroneous calculation of Gaussian path integrals and has nothing to do with the momentum recoil of a particle interacting with an external bath.