Background Field Functional Renormalization Group for Absorbing State Phase Transitions

TL;DR

This paper introduces a background field functional renormalization group method for analyzing absorbing state phase transitions, providing accurate critical exponent estimates for directed percolation universality class.

Contribution

It develops a novel background field approach within the functional renormalization group framework for absorbing state phase transitions, improving critical exponent predictions.

Findings

Accurately estimates critical exponents in low dimensions.

Demonstrates effectiveness of background field method for directed percolation.

Provides a new analytical tool for phase transition studies.

Abstract

We present a functional renormalization group approach for the active to inactive phase transition in directed percolation type systems, in which the transition is approached from the active, finite density phase. By expanding the effective potential for the density field around its minimum, we obtain a background field action functional, which serves as a starting point for the functional renormalization group approach. Due to the presence of the background field, the corresponding non-perturbative flow equations yield remarkably good estimates for the critical exponents of the directed percolation universality class, even in low dimensions.