IAS Amplitudes Group Meeting
Nonlinear Love Numbers of Black Holes and Neutron Stars
Abstract: Love numbers quantify how compact objects deform under external tidal fields. They are key gravitational wave observables and provide a direct probe of compact-object structure. At linear order, black hole (BH) Love numbers vanish - a consequence of the hidden symmetries of linear BH perturbations. I will show that this BH property persists beyond the linear regime. For neutron stars, Love numbers are sensitive to the equation of state.
Motivated by upcoming detectors, I will present calculations of nonlinear neutron-star Love numbers by matching relativistic stellar perturbations to the worldline effective field theory (EFT). Finally, I will discuss resonant couplings between orbital motion and stellar deformations and their incorporation into the worldline EFT.