Chiral Gauge Theory at the Boundary between Topological Phases

Phys Rev Lett. 2024 Apr 5;132(14):141603. doi: 10.1103/PhysRevLett.132.141603.

Abstract

I demonstrate how chiral fermions with an exact gauge symmetry can appear on the d-dimensional boundary of a finite volume (d+1)-dimensional manifold, without any light mirror partners. The condition for the d-dimensional boundary theory to be local is that gauge anomalies cancel and that the volume be large. This can likely be achieved on a lattice and provides a new paradigm for the lattice regularization of chiral gauge theories.