NBIA Seminar with Elias Most (Princeton): Probing dense matter with binary neutron star mergers

Neutron stars are fascinating laboratories for strong gravity, multi-messenger astronomy and nuclear physics. With the advent of multi-messenger detections of neutron star merger gravitational wave events by the Laser Interferometer Gravitational-Wave Observatory (LIGO), we now have an unprecedented opportunity to study neutron stars and their rich phenomenology.
In this talk, I will review how the merger of two neutron stars can shed light on the behavior of nuclear matter at densities that are difficult to probe with ground-based experiments. More specifically, I will discuss how the size and maximum mass of neutron stars are related to their nuclear composition, and how we can constrain these macroscopic quantities with previously detected gravitational wave events.
In the second part of the talk, we will go beyond the presently observed inspiral phase of a binary neutron star coalescence, and focus on post-merger observables. I will discuss how properties of dense nuclear matter, such as the nuclear symmetry energy, the appearance of deconfined quarks and out-of-(weak-) equilibrium effects are affecting the post-merger gravitational wave signal. Understanding these various contributions to the post-merger evolution will be key to interpreting next-generation gravitational wave detections.