Lattice studies of quantum chromodynamics-like theories with many fermionic degrees of freedom

Abstract

I give an elementary introduction to the study of gauge theories coupled to fermions with many degrees of freedom. Besides their intrinsic interest, these theories are candidates for non-perturbative extensions of the Higgs sector of the standard model. While related to quantum chromodynamics, these systems can exhibit very different behaviour from it: they can possess a running gauge coupling with an infrared-attractive fixed point. I briefly survey recent lattice work in this area.