Exotic Compact Objects: The Dark White Dwarf

TL;DR

This paper explores the theoretical properties and gravitational wave signatures of dark white dwarfs, exotic compact objects made of dark matter, and discusses how their detection could reveal properties of dark matter particles.

Contribution

It introduces a detailed model of dark white dwarfs, confirms their unique properties through relativistic analysis, and demonstrates their potential detectability via gravitational waves.

Findings

Dark white dwarfs have distinct masses and tidal deformabilities.

Gravitational wave observations can constrain dark matter particle properties.

Universal relations similar to neutron star Love relations are found for dark white dwarfs.

Abstract

Several dark matter models allow for the intriguing possibility of exotic compact object formation. These objects might have unique characteristics that set them apart from their baryonic counterparts. Furthermore, gravitational wave observations of their mergers may provide the only direct window on a potentially entirely hidden sector. Here we discuss dark white dwarfs, starting with an overview of the microphysical model and analytic scaling relations of macroscopic properties derived from the non-relativistic limit. We use the full relativistic formalism to confirm these scaling relations and demonstrate that dark white dwarfs, if they exist, would have masses and tidal deformabilities that are very different from those of baryonic compact objects. Further, and most importantly, we demonstrate that dark white dwarf mergers would be detectable by current or planned gravitational observatories across several orders of magnitude in the particle-mass parameter space. Lastly, we find universal relations analogous to the compactness-Love and binary Love relations in neutron star literature. Using these results, we show that gravitational wave observations would constrain the properties of the dark matter particles constituting these objects.