Tricks to implement the overlap Dirac operator

I present several tricks to help implement the overlap Dirac operator numerically.Comment: 3 pages, latex, espcrc2.st

Lattice Chirality

The external fermion propagator and the internal fermion propagator in the overlap are given by different matrices. A generic problem (formulated by Pelissetto) faced by all chiral, non-local, propagators of Rebbi type is avoided in this manner. Nussinov-Weingarten-Witten mass inequalities are exactly preserved. It is sketched how to obtain simple lattice chiral Yukawa models and simple expressions for covariant currents. Going beyond my oral presentation, I have added to the write-up several comments on Niedermayer's talk. His transparencies are available on the internet.Comment: LATTICE98(chiral

The fourth root of the Kogut-Susskind determinant via infinite component fields

An example of interpolation by means of local field theories between the case of normal Kogut-Susskind fermions and the case of keeping just the fourth root of the Kogut-Susskind determinant is given. For the fourth root trick to be a valid approximation certain limits need to be smooth. The question about the validity of the fourth root trick is not resolved, only cast into a local field theoretical framework.Comment: 2

Exactly massless quarks on the lattice

It is suggested that the fermion determinant for a vector-like gauge theory with strictly massless quarks can be represented on the lattice as $\det{{1+V}\over 2}$, where $V=X(X^\dagger X)^{-1/2}$ and $X$ is the Wilson-Dirac lattice operator with a negative mass term. There is no undesired doubling and no need for any fine tuning. Several other appealing features of the formula are pointed out.Comment: 7 pages, plain TeX; references correcte

Wavelets and Lattice Field Theory

When continuous fields are expanded in a wavelet basis, a D-dimensional continuum action becomes a (D+1)-dimensional lattice action on the naively discretized Poincare-patch coordinates of an Euclidean AdS(D+1). New possible criteria for acceptable actions open up.Comment: 7 pages. Contribution to Lattice2017, 18-24 June, Granada, Spai