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arXiv · 1607.08621

Gravitationally bound BCS state as dark matter

Stephon Alexander·Sam Cormack
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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 Bogoliubov-de 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 self-gravitating, superfluid solution for dark matter halos. In order to produce halos the size of dwarf galaxies, we require a particle mass of $\sim 200\mathrm{eV}$. 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.

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Stephon Alexander, Sam Cormack. 2016-07-28. Gravitationally bound BCS state as dark matter. https://doi.org/10.1088/1475-7516%2F2017%2F04%2F005

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