A lattice formulation for chiral gauge theory?

David Kaplan
Friday, December 16, 2016
Combining five dimensional domain wall fermions in Euclidian space with gauge fields that undergo gradient flow in the fifth dimension can can lead to a gauge theory of interacting chiral fermions on one boundary, and "fluff" on the other: mirror fermions which do not interact with gauge fields except through their topology. I describe how this works and attempts to formulate the effective four dimensional lattice theory of the surface modes. Can this serve as a nonperturbative regulator for chiral gauge theories? Does the existence of "fluff" imply new phenomenology for these theories?