Non-perturbative evolution equations for the tricritical theory

TL;DR

This paper derives non-perturbative evolution equations for the tricritical scalar theory, identifying a stable fixed point in three dimensions for large N, advancing understanding of its critical behavior.

Contribution

It introduces non-perturbative beta functions for the tricritical theory using an exact evolution equation, confirming fixed point existence beyond large N approximations.

Findings

Existence of an ultraviolet stable fixed point for N>4 in d=3

Non-perturbative beta functions derived for d≤3

Fixed point confirmed beyond 1/N expansion assumptions

Abstract

The N component scalar tricritical theory is considered in a non-perturbative setting. We derive non-perturbative beta functions for the relevant couplings in $d\leq 3$. The beta functions are obtained through the use of an exact evolution equation for the so called effective average action. In d=3 it is established the existence of an ultraviolet stable fixed point for N>4. This confirms earlier results obtained using the 1/N expansion where such a fixed point is believed to exist at least for $N\gtrsim 1000$.