Reshaping our understanding on structure formation with the quantum nature of the dark matter

TL;DR

This paper introduces a thermodynamic approach to model non-linear structure formation in cosmology, accounting for the quantum nature of dark matter, and addresses key open questions about dark matter properties and black hole formation.

Contribution

It presents a novel thermodynamic method for collisionless fermionic dark matter, providing insights into structure formation and black hole origins beyond traditional N-body simulations.

Findings

Supports fermionic dark matter as a solution to the core-cusp problem

Provides constraints on dark matter particle mass and nature

Offers explanations for early supermassive black hole formation

Abstract

We study the non-linear structure formation in cosmology accounting for the quantum nature of the dark matter (DM) particles in the initial conditions at decoupling, as well as in the relaxation and stability of the DM halos. Differently from cosmological N-body simulations, we use a thermodynamic approach for collisionless systems of self-gravitating fermions in General Relativity, in which the halos reach the steady state by maximizing a coarse-grained entropy. We show the ability of this approach to provide answers to crucial open problems in cosmology, among others: the mass and nature of the DM particle, the formation and nature of supermassive black holes in the early Universe, the nature of the intermediate mass black holes in small halos, and the core-cusp problem.