The absence of cut-off effects for the fixed-point action in one-loop perturbation theory Original Research Article

In order to support the formal renormalization group arguments that the fixed-point action of an asymptotically free model gives cut-off independent physical predictions in one-loop perturbation theory, we calculate the finite-volume mass gap m(L) in the non-linear σ-model. No cut-off effect of the type g4 (a/L)n is seen for any n. The results are compared with those of the standard and tree level improved symanzik actions.