Unifying the Strengths of Forces in Higher Dimensions

Abstract

We consider the embedding of the Standard Model fields in a $(4+d)$-dimensional theory while gravitons may propagate in $d^{\prime }$ extra, compact dimensions. We study the modification of strengths of the gravitational and gauge interactions and, for various values of $d$ and $d^{\prime }$, we determine the energy scale at which these strengths are unified. Special cases where the unification of strengths is characterized by the absence of any hierarchy problem are also presented.

Comments: 4 pages, Revtex, no figures, a volume factor added in eq.(11), cases (iii) and (iv) slightly rearranged, comments added