Dynamical Selection of Critical Exponents

TL;DR

This paper explores a novel scenario in renormalized field theories where a dynamical mechanism selects a single fixed point from an infinite family, especially in systems with attractive interactions and potentials vanishing at large field values.

Contribution

It introduces a new dynamical selection process for fixed points in systems with specific attractive potentials, expanding understanding beyond traditional fixed-point structures.

Findings

Identifies a scenario where only one fixed point is selected from an infinite family.

Demonstrates the role of attractive interactions with potentials vanishing at large fields.

Provides insights into fixed-point selection mechanisms in field theories.

Abstract

In renormalized field theories there are in general one or few fixed points which are accessible by the renormalization-group flow. They can be identified from the fixed-point equations. Exceptionally, an infinite family of fixed points exists, parameterized by a scaling exponent $\zeta$, itself function of a non-renormalizing parameter. Here we report a different scenario with an infinite family of fixed points of which seemingly only one is chosen by the renormalization-group flow. This dynamical selection takes place in systems with an attractive interaction ${\cal V}(\phi)$, as in standard $\phi^4$ theory, but where the potential $\cal V$ at large $\phi$ goes to zero, as e.g. the attraction by a defect.