Comment on hep-lat/9901005 v1-v3 by W. Bietenholz

TL;DR

This paper critiques a recent claim about the non-ultralocality of Ginsparg-Wilson fermions, questioning the validity of the proof for all such fermions and discussing the evolution of related literature.

Contribution

It provides a critical commentary on the validity of a recent proof regarding Ginsparg-Wilson fermions and contextualizes the development of this claim within existing literature.

Findings

The claim in v3 may not be fully substantiated.

Evolution of the paper versions reflects ongoing debate.

Literature context highlights unresolved issues.

Abstract

I comment on the above paper(s) discussing the issue of non-ultralocality for Ginsparg-Wilson fermionic actions. The purpose of this note is to point out that the new claim in "v3" (Feb 24, 2000), alleging the proof for "all Ginsparg-Wilson fermions", might not be substantiated. The remarkable evolution of versions of this paper is put in context with the literature existing at the time of their appearance.