Renormalization of the delta expansion in curved space-time.

Abstract

Renormalization of a recently proposed $\ensuremath{\delta}$ expansion for a self-interacting scalar field theory in curved space-time is examined. The explicit calculation is carried out up to order ${\ensuremath{\delta}}^{2}$, which indicates that the expansion is renormalizable, but reduces to essentially the $\ensuremath{\lambda}{\ensuremath{\varphi}}^{4}$ theory when the cutoff is removed. A similar conclusion has been reached in a previous paper where the case of flat space-time is considered.