Analytical results for the four-loop RG functions in the 2D non-linear O(n) {\sigma}-model on the lattice

Abstract

We recalculate four-loop renormalization group functions in 2-dimensional nonlinear O(n) {\sigma}-model using coordinate-space method. The high accuracy of calculation allow us to find the analytical form of {\beta}- and {\gamma}-function (anomaluos dimension).

Comments: 4 pages