Simulated Dark-Matter Halos as a Test of Nonextensive Statistical Mechanics

TL;DR

This paper tests the applicability of nonextensive statistical mechanics to dark-matter halos by comparing theoretical stellar polytropes with simulated halo structures, finding significant inconsistencies.

Contribution

It provides a critical evaluation of nonextensive statistical mechanics in modeling self-gravitating systems, highlighting its limitations for dark-matter halos.

Findings

Density profiles of stellar polytropes do not match simulated halos

No polytropic index n yields consistent results

Suggests reconsidering the use of nonextensive mechanics for such systems

Abstract

In the framework of nonextensive statistical mechanics, the equilibrium structures of astrophysical self-gravitating systems are stellar polytropes, parameterized by the polytropic index n. By careful comparison to the structures of simulated dark-matter halos we find that the density profiles, as well as other fundamental properties, of stellar polytropes are inconsistent with simulations for any value of n. This result suggests the need to reconsider the applicability of nonextensive statistical mechanics (in its simplest form) to equilibrium self-gravitating systems.