Domain Walls in Large-$N$ QCD$_3$

Abstract

Large-$N$ three dimensional QCD with a level $k$ Chern-Simons term and $N_f$ massless flavours admits $N_f+1$ degenerate vacua. We discuss various aspects of the domain walls that interpolate between those vacua. Using a bosonic dual for the case $k \ge N_f/2$ we write down the profile of the composite wall. By fluctuating the profile, we find the 2d field theory that lives on the wall, a level-$N$ gauged WZW model, and compare it with a theory that was previously obtained by using anomaly inflow considerations. We also discuss the case $k < N_f/2$. Finally, we remark on the realisation of the wall as a D-brane in a holographic dual.