Speaker
Description
We propose a way to formulate a realistic chiral gauge theory like the standard model on a lattice (or a general simplicial complex in curved spacetime), so that it has the correct continuum limit, with the correct symmetries and (co)homological properties, and no unwanted doublers or anomalies. Building on recent ideas of Catterall and collaborators, our approach uses restricted Kahler-Dirac fermions (spinors with a dual interpretation as differential forms). To obtain the right continuum limit, we find we must appropriately couple the Kahler-Dirac fermions to the tetrad and spin connection one-forms (which describe the geometry of spacetime). Conceptually, the crucial new point in our formulation is to carefully distinguish between the diffeomorphism group (which is broken by discretization) and the local Lorentz group (which is exactly preserved). (In collaboration with Vatsalya Vaibhav.)