On the Vafa-Witten Theorem on Spontaneous Breaking of Parity

Abstract

We revisit the proof provided by Vafa and Witten that there is no spontaneous parity breaking in theories with vector-like fermions. We argue that the various criticisms that have been leveled at the original proof do not invalidate it.

Comments: 11 pages, no figures, requires revtex4; corrections concerning the applicability of the theorem to lattice models are included