Flow of low energy couplings in the Wilson renormalization group

Abstract

A new form of the Wilson renormalization group equation is derived, in which the flow equations are, up to linear terms, proportional to a gradient flow. A set of co\"ordinates is found in which the flow of marginal, low-energy, couplings takes a gradient form, if relevant couplings are tuned to vanish.Comment: 9 pages, RevTeX. Version to appear in Phys. Rev.