Event

One can probe nuclear physics with gravitational waves from a binary neutron star merger through measurements of a tidal Love number. The latter is a linear response coefficient of the stellar quadrupole moment to the external tidal field and depends sensitively on the internal structure of a neutron star. The Love number of black holes, on the other hand, is known to vanish in General Relativity (GR). Measurements of these Love numbers can, in principle, also be used to probe strong-field gravity. After reviewing the current status of neutron star observations and how to compute Love numbers in GR, I will describe my recent works on calculating Love numbers for astrophysical compact objects in theories beyond GR. I will first introduce a general perturbative framework to compute Love numbers for black holes in non-GR theories. I will next explain how to calculate Love numbers for neutron stars in beyond-GR theories, taking scalar-tensor theories as an example, including new types of Love numbers that arise due to the presence of the scalar field.