Gravitationally bound BCS state as dark matter
Abstract
We explore the possibility that fermionic dark matter undergoes a BCS transition to form a superfluid. This requires an attractive interaction between fermions and we describe a possible source of this interaction induced by torsion. We describe the gravitating fermion system with the Bogoliubovde Gennes formalism in the local density approximation. We solve the Poisson equation along with the equations for the density and gap energy of the fermions to find a selfgravitating, superfluid solution for dark matter halos. In order to produce halos the size of dwarf galaxies, we require a particle mass of ~ 200 eV. We find a maximum attractive coupling strength before the halo becomes unstable. If dark matter halos do have a superfluid component, this raises the possibility that they contain vortex lines.
 Publication:

Journal of Cosmology and Astroparticle Physics
 Pub Date:
 April 2017
 DOI:
 10.1088/14757516/2017/04/005
 arXiv:
 arXiv:1607.08621
 Bibcode:
 2017JCAP...04..005A
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Phenomenology;
 High Energy Physics  Theory
 EPrint:
 16 pages, 3 figures, version accepted for publication in JCAP