Astrophysical Signatures of Fermionic Dark Matter

Abstract

Fermionic dark matter particles remain one of the most compelling candidates for the dark matter content of the Universe, yet no positive results have been obtained from direct detection experiments. In this work, we investigate the possibility that such particles form compact gravitationally bound objects supported by degeneracy pressure. Through an extensive review of microlensing surveys, we derive constraints on the masses of these compact objects. We further analyze the accretion of baryonic matter onto these objects and evaluate their thermal and radiative properties. The estimated burst emission is found to be well below the energies associated with the Galactic Center GeV excess, suggesting that these compact objects are unlikely to be the source of the observed signal. Our analysis suggests that admixed dark matter and baryonic matter objects could potentially account for a fraction of the presently unobserved baryonic matter, thereby providing a possible explanation for a fraction of the missing baryons in the Universe.