Evidence of fluctuation-induced first-order phase transition in active matter

TL;DR

This paper investigates how birth and death processes in active matter lead to suppressed density fluctuations and induce a fluctuation-driven first-order phase transition, analyzed through perturbative renormalization group methods.

Contribution

It demonstrates that Malthusian active matter undergoes a fluctuation-induced first-order transition due to birth/death dynamics, extending understanding of phase behavior in active systems.

Findings

Density fluctuations are partially suppressed by birth/death processes.

RG flow indicates an unstable region leading to a first-order transition.

The transition is fluctuation-induced, not mean-field driven.

Abstract

We study the properties of the Malthusian Toner-Tu theory in its near ordering phase. Because of the birth/death process, characteristic of this Malthusian model, density fluctuations are partially suppressed. We study this model using the perturbative renormalization group. At one loop we find that the renormalization group flow drives the system in an unstable region, suggesting a fluctuation-induced first-order phase transition.