Anomaly matching, (axial) Schwinger models, and high-T super Yang-Mills domain walls

Abstract

We study the discrete chiral- and center-symmetry ’t Hooft anomaly matching in the charge-q two-dimensional Schwinger model. We show that the algebra of the discrete symmetry operators involves a central extension, implying the existence of q vacua, and that the chiral and center symmetries are spontaneously broken. We then argue that an axial version of the q = 2 model appears in the worldvolume theory on domain walls between center-symmetry breaking vacua in the high-temperature SU(2) N=1 super-Yang-Mills theory and that it inherits the discrete ’t Hooft anomalies of the four-dimensional bulk. The Schwinger model results suggest that the high-temperature domain wall exhibits a surprisingly rich structure: it supports a non-vanishing fermion condensate and perimeter law for spacelike Wilson loops, thus mirroring many properties of the strongly coupled four-dimensional low-temperature theory. We also discuss generalizations to theories with multiple adjoint fermions and possible lattice tests.