Phase transitions in self-gravitating systems and bacterial populations with a screened attractive potential

TL;DR

This paper investigates phase transitions in systems with screened attractive potentials, revealing diverse behaviors depending on spatial dimension and screening length, with applications to astrophysics and bacterial chemotaxis.

Contribution

It introduces a unified analysis of phase transitions in screened Newtonian systems, linking gravitational and biological models through a common framework.

Findings

Diverse phase transition types depending on dimension and screening length

Identification of conditions for homogeneous and inhomogeneous states

Application to both astrophysical and biological systems

Abstract

We consider a system of particles interacting via a screened Newtonian potential and study phase transitions between homogeneous and inhomogeneous states in the microcanonical and canonical ensembles. Like for other systems with long-range interactions, we obtain a great diversity of microcanonical and canonical phase transitions depending on the dimension of space and on the importance of the screening length. We also consider a system of particles in Newtonian interaction in the presence of a ``neutralizing background''. By a proper interpretation of the parameters, our study describes (i) self-gravitating systems in a cosmological setting, and (ii) chemotaxis of bacterial populations in the original Keller-Segel model.