On the Burnside-Brauer-Steinberg theorem

A well-known theorem of Burnside says that if $\rho$ is a faithful representation of a finite group $G$ over a field of characteristic $0$, then every irreducible representation of $G$ appears as a constituent of a tensor power of $\rho$. In 1962, R. Steinberg gave a module theoretic proof that simultaneously removed the constraint on the characteristic, and allowed the group to be replaced by a monoid. Brauer subsequently simplified Burnside's proof and, moreover, showed that if the character of $\rho$ takes on $r$ distinct values, then the first $r$ tensor powers of $\rho$ already contain amongst them all of the irreducible representations of $G$ as constituents. In this note we prove the analogue of Brauer's result for finite monoids. We also prove the corresponding result for the symmetric powers of a faithful representation.