Physical Review Letters
Skeleton Graph Expansion for Critical Exponents
T. Tsuneto, Elihu Abrahams
Abstract
Critical exponents are calculated using conventional many-body perturbation theory by means of a self-consistent skeleton graph expansion in $4\ensuremath{-}\ensuremath{\epsilon}$ deminsions, where $\ensuremath{\epsilon}$ is small. The self-consistency is expressed through Ward identities. The results, the same as those of Wilson, are obtained without recourse to renormalization group arguments.