Coalescence of Exotic Compact Objects in the new era of gravitational wave astronomy

Abstract

The direct detection of gravitational waves by LIGO and Virgo interferometric observatories has opened a new multi-messenger era to study some of the most energetic phenomena occurring in the Universe. Although the detections are so far consistent with the coalescence of binary black holes and inspiral binary neutron stars systems, in the future we could detect gravitational waves from new binary systems composed of different compact objects. These putative Exotic Compact Objects (ECOs) could exist in theory but have not yet been found in Nature, since they are supposed to be too dim to be detected by current electromagnetic telescopes. In this Thesis we study, through full three dimensional numerical relativity simulations, the dynamics of these ECOs and the gravitational radiation emitted during their coalescence, focusing in binaries formed by boson stars (i.e., self-gravitating objects modeled with a complex scalar field), dark matter stars (i.e., astrophysical compact objects that only interact with other stars through gravity) and neutron stars with a small fraction of dark matter on their interiors (i.e., modeled by mixed fermion-boson stars). Gravitational waves from the coalescence of compact objects play an important role probing gravity in the strong-field regime. Hence, our studies are crucial to discriminate whether future non-standard gravitational wave detections come from unknown sources such as ECOs. Consequently, exploring the signature of these gravitational waves could reveal their existence.