Quiver Approach to Massive Gauge Bosons Beyond the Standard Model

We address the question of the possible existence of massive gauge bosons beyond the $W^{\pm}$ and $Z^{0}$ of the standard model. Our intuitive and aesthetic approach is based on quiver theory. Examples thereof arise, for example, from compactification of the type IIB superstring on $AdS_5 \times S_5/ Z_n$ orbifolds. We explore the quiver theory framework more generally than string theory. The practical question is what gauge bosons to look for at the upgraded LHC, in terms of color and electric charge, and of their couplings to quarks and leptons. Axigluons and bileptons are favored.