Dark stars and gravitational waves: Topical review

Abstract

Motivated by recent observations of compact binary gravitational wave events reported by LIGO/Virgo/KAGRA, we review the basics of dark and hybrid stars11In this review “hybrid stars” means “dark-matter admixed stars”, though this term usually refers to compact stars that compose of both hadronic and quark matter. and examine their probabilities as mimickers for black holes and neutron stars. This review aims to survey this exciting topic and offer the necessary tools for the research study at the introductory level. Although called a review, some results are newly derived, such as the equations of state for specific dark star models and the scaling symmetry for the Tidal Love number.