Dimensional Reduction of a Generalized Flux Problem

A generalized flux problem with Abelian and non-Abelian fluxes is considered. In the Abelian case we shall show that the generalized flux problem for tight-binding models of noninteracting electrons on either $2n$ or $2n+1$ dimensional lattice can always be reduced to a $n$ dimensional hopping problem. A residual freedom in this reduction enables to identify equivalence classes of hopping Hamiltonians which have the same spectrum. In the non-Abelian case the reduction is not possible in general unless the flux tensor factorizes into an Abelian one times an element of the corresponding algebra.