Some Answered and Unanswered Questions About the Structure of the Set of Fermionic Actions with GWL Symmetry

Abstract

Several issues related to the question "How simple can Ginsparg-Wilson fermionic actions be?" are discussed, and it is suggested that simplicity in the eigenspace should be looked for.

Comments: 8 pages, 2 figures, Contribution to the workshop "Lattice Fermions and Structure of the Vacuum", Oct 5-9, 1999, Dubna, Russia. Equation on page 7 corrected. Typo related to eq.(2) corrected. Two formulations made more clear