Tree-level renormalization

TL;DR

This paper investigates how saddle point structures in the N-component scalar model influence renormalization group flow, revealing flat actions and phase separation phenomena with exact and mean-field results.

Contribution

It demonstrates that saddle point structures can generate non-trivial RG flow and provides an exact flat action solution valid to all loop orders.

Findings

Saddle point structures induce non-trivial RG flow.

Flat action is obtained as an exact result.

Correlation functions are computed in mean-field approximation.

Abstract

It is shown in the framework of the N-component scalar model that the saddle point structure may generate non-trivial renormalization group flow. The spinodal phase separation can be described in this manner and a flat action is found as an exact result which is valid up to any order of the loop expansion. The correlation function is computed in a mean-field approximation.