The Absence of Ultralocal Ginsparg-Wilson Fermions
arXiv:hep-lat/9901005
Abstract
It was shown recently by I. Horvath that lattice fermions obeying the standard form of the Ginsparg-Wilson relation cannot be ultralocal. However, there are more general forms of the Ginsparg-Wilson relation, which also guarantee the physical properties related to chirality, but which are not covered by Horvath's consideration. Here we present a proof which applies to all Ginsparg-Wilson fermions, demonstrating that they can only be local in the sense of an exponential decay of their couplings, but not ultralocal.
arXiv comment9 pages, proof extended to absolutely all Ginsparg-Wilson fermions