ONE-LOOP FINITE-TEMPERATURE EFFECTIVE ACTION FOR COMPOSITE FIELDS IN CURVED SPACE

We obtain high temperature results for the one-loop effective action f or composite fields in interaction with an Abelian gauge field and min imally coupled to gravity in a curved background space-time, using the Vilkovisky-DeWitt approach, by making a local expansion in the Rieman n tenser and its derivatives. We also give results for the fields mini mally coupled to gravity in an arbitrary curved background space-time at zero temperature, and for the case where the fields are nonminimall y coupled to gravity in Euclidean de Sitter space. The results obtaine d are gauge-invariant and gauge-condition-independent on-shell as well as off-shell.