Infinite-noise criticality: Nonequilibrium phase transitions in fluctuating environments

TL;DR

This paper investigates how time-dependent environmental noise influences nonequilibrium phase transitions, revealing a new type of criticality characterized by infinite noise and broad fluctuations, supported by theoretical and simulation evidence.

Contribution

It introduces a real-time renormalization-group framework for understanding infinite-noise criticality caused by temporal disorder in nonequilibrium systems.

Findings

Identification of a new critical point with diverging noise amplitude

Demonstration of broad, infinite distributions of density at criticality

Validation of theory through computer simulations

Abstract

We study the effects of time-varying environmental noise on nonequilibrium phase transitions in spreading and growth processes. Using the examples of the logistic evolution equation as well as the contact process, we show that such temporal disorder gives rise to a distinct type of critical points at which the effective noise amplitude diverges on long time scales. This leads to enormous density fluctuations characterized by an infinitely broad probability distribution at criticality. We develop a real-time renormalization-group theory that provides a general framework for the effects of temporal disorder on nonequilibrium processes. We also discuss how general this exotic critical behavior is, we illustrate the results by computer simulations, and we touch upon experimental applications of our theory.