In this article, I introduce ideas and techniques to extract information about the equation of
state of matter at very high densities from gravitational waves emitted before, during and …

Neutron stars and quark stars are ideal laboratories to study fundamental physics at supra
nuclear densities and strong gravitational fields. Astrophysical observables, however …

The dawn of the twenty-first century came with very positive prospects for gravity, cosmology,
and astrophysics. Technological progress made it possible for cosmology to enter to its …

The Advanced LIGO [1] and Advanced Virgo [2] detectors have made numerous detections
of gravitational waves (GWs), to date consisting of short-duration (transient) GWs emitted …

One century after its formulation, Einstein's general relativity (GR) has made remarkable
predictions and turned out to be compatible with all experimental tests. Most of these tests …

General Relativity has shown an outstanding observational success in the scales where it
has been directly tested. However, modifications have been intensively explored in the …

Perturbations of black holes, initially considered in the context of possible observations of
astrophysical effects, have been studied for the past 10 years in string theory, brane-world …

The nuclear symmetry energy characterizes the variation of the binding energy as the
neutron to proton ratio of a nuclear system is varied. This is one of the most important …

The exterior gravitational field of a slowly rotating neutron star can be characterized by its
multipole moments, the first few being the neutron star mass, moment of inertia, and …

Gravitational-wave observations by the laser interferometer gravitational-wave observatory
(LIGO) and Virgo have provided us a new tool to explore the Universe on all scales from …