Chiral and Gravitational Anomalies on Fermi Surfaces

Understand

A Fermi surface threaded by a Berry phase can be described by the Wess-Zumino-Witten (WZW) term.

• After gauging, it produces a five-dimensional Chern-Simons term in the action.
• We show how this Chern-Simons term captures the essence of the Abelian, non-Abelian, and mixed gravitational anomalies in describing both in- and off-equilibrium phenomena.
• In particular we derive a novel contribution to the Chiral Vortical Effect that arises when a temperature gradient is present.