Effective one-loop Lagrangian for gauged scrH/scrK sigma models.

Abstract

We determine the divergent one-loop contributions to the effective action for a gauged nonlinear \ensuremath{\sigma} model in which the scalars are valued on the coset space scrH/scrK of a noncompact group scrH, with scrK its maximally compact subgroup. We focus especially on the scalar+Yang-Mills sector of a class of no-scale supergravity models suggested by superstrings. The formalism developed should be applicable to a broader class (with compact or noncompact scrH) of interesting models.