Comment on ``Exact bosonization for an interacting Fermi gas in arbitrary dimensions''

TL;DR

This paper critically analyzes Efetov et al.'s bosonization method, showing it is equivalent to an existing approach and shares the same sign problem, thus questioning its claimed advantages.

Contribution

It clarifies the relationship between Efetov et al.'s method and the BSS approach, highlighting the persistence of the sign problem.

Findings

Efetov et al.'s method is a reformulation of BSS approach

The sign problem remains unchanged in the reformulation

Dependence of the sign on path smoothness is confirmed

Abstract

This a comment on arXiv:0907.3243v2. We demonstrate that the method proposed by Efetov {\it et. al.} is just a reformulation of the Blankenbeckler, Scalapino, and Sugar approach and thus it contains exactly the same sign problem, including the dependence of the sign on the smoothness of the paths.