paper

The Logotropic Dark Fluid as a unification of dark matter and dark energy

arXiv:1505.00034 · doi:10.1016/j.physletb.2016.04.042

Abstract

We propose a heuristic unification of dark matter and dark energy in terms of a single dark fluid with a logotropic equation of state , where is the rest-mass density, is the Planck density, and is the logotropic temperature. The energy density is the sum of a rest-mass energy term mimicking dark matter and an internal energy term mimicking dark energy. The logotropic temperature is approximately given by , where is the cosmological density. More precisely, we obtain that we interpret as a fundamental constant. At the cosmological scale, this model fullfills the same observational constraints as the CDM model. However, it has a nonzero velocity of sound and a nonzero Jeans length which, at the beginning of the matter era, is about , in agreement with the minimum size of the dark matter halos observed in the universe. At the galactic scale, the logotropic pressure balances gravitational attraction and solves the cusp problem and the missing satellite problem. The logotropic equation of state generates a universal rotation curve that agrees with the empirical Burkert profile of dark matter halos up to the halo radius. In addition, it implies that all the dark matter halos have the same surface density and that the mass of dwarf galaxies enclosed within a sphere of fixed radius has the same value , in remarkable agreement with the observations.

arXiv admin note: substantial text overlap with arXiv:1504.08355

References in corpus (7)

Cited by in corpus (29)