Non-perturbative equivalences among large N gauge theories with adjoint and bifundamental matter fields
Pavel Kovtun, Mithat Unsal, Laurence G. Yaffe
TL;DR
The paper establishes a non-perturbative large-$N_{ m c}$ equivalence between a parent $U(N_{ m c})$ gauge theory with adjoint matter and its orbifold daughter theories by comparing their loop equations on a lattice. It shows that, in the strong-coupling/large-mass regime and with unbroken orbifold and theory-space symmetries, the loop equations of the parent and daughter theories coincide after an appropriate rescaling of couplings, implying identical predictions for Wilson-loop observables, string tensions, and particle spectra. The authors extend the loop-equation framework to decorated Wilson loops with both scalars and fermions via an extended lattice construction, and demonstrate that the non-perturbative equivalence holds for single-trace and two-loop connected correlators. They discuss how symmetry realizations constrain the mapping and acknowledge limitations to phases with broken symmetries, while outlining potential generalizations to more complex orbifolds and beyond the strong-coupling regime. Overall, the work provides a rigorous, non-perturbative foundation for large-$N_{ m c}$ orbifold equivalences in a broad class of gauge theories, independent of supersymmetry or continuum limits.
Abstract
We prove an equivalence, in the large N limit, between certain U(N) gauge theories containing adjoint representation matter fields and their orbifold projections. Lattice regularization is used to provide a non-perturbative definition of these theories; our proof applies in the strong coupling, large mass phase of the theories. Equivalence is demonstrated by constructing and comparing the loop equations for a parent theory and its orbifold projections. Loop equations for both expectation values of single-trace observables, and for connected correlators of such observables, are considered; hence the demonstrated non-perturbative equivalence applies to the large N limits of both string tensions and particle spectra.
