The effective exponent γ(Q) and the slope of the β function

Abstract

The slope of the β function at a fixed point is commonly thought to be RG invariant and to be the critical exponent γ* that governs the approach of any physical quantity RR to its fixed-point limit: R*−R∝Qγ*. Chýla has shown that this is not quite true. Here we define a proper RG invariant, the “effective exponent” γ(Q), whose fixed-point limit is the true γ*.