Ringdown of charged compact objects using membrane paradigm

Although black holes are an integral part of the standard model of astrophysics and cosmology, their existence poses some serious fundamental problems. In recent years, several horizonless compact object models were proposed to address those issues. As gravitational-wave detectors observe more and more merger events with large signal-to-noise ratios, gravitational-wave spectroscopy could hold the key to uncovering the existence of these objects. This is because the late-time ringdown signals of horizonless compact objects differ from those of black holes. In this paper, we study the ringdown properties of charged compact objects and compare them with those obtained in the black hole scenario. Since the internal structure and equation of state of these compact objects are largely unknown, we employ the membrane paradigm to obtain appropriate boundary conditions for the perturbations of these objects. This model can describe the ringdown properties of a large variety of compact objects.