Universal structure of two and three dimensional self-gravitating systems in the quasi-equilibrium state

TL;DR

This paper demonstrates that two- and three-dimensional self-gravitating systems share a universal density profile in quasi-equilibrium, supported by numerical simulations and a phenomenological Langevin model.

Contribution

It introduces a phenomenological Langevin model with distinctive noise to explain the universal density structure of self-gravitating systems in different dimensions.

Findings

Two-dimensional systems have similar density profiles to three-dimensional ones.

The theoretical density profile matches observational and simulation data.

A new Langevin-based model explains the universal structure.

Abstract

We study a universal structure of two and three dimensional self-gravitating systems in the quasi-equilibrium state. It is shown numerically that the two dimensional self-gravitating system in the quasi-equilibrium state has the same kind of density profile as the three dimensional one. We develop a phenomenological model to describe this universal structure by using a special Langevin equation with a distinctive random noise to self-gravitating systems. We find that the density profile derived theoretically is consistent well with results of observations and simulations.