Nonlinear Love numbers of non-rotating black holes and neutron stars

概要

Tidal Love numbers quantify the deformability of compact objects under external tidal fields and are key quantities in gravitational‑wave astronomy. They are essential for accurately modeling waveforms during the final orbits of an inspiral and are tightly connected to the microphysics of the compact object. At linear order, the tidal Love numbers of Schwarzschild black holes are famously zero. I will show that this property persists beyond linear order. In contrast, neutron stars exhibit a finite tidal response that encodes information about their internal structure, including their equation of state. I will present a framework for computing their tidal Love numbers beyond linear order. As I will discuss, these calculations rely on carefully matching relativistic perturbation theory of compact objects with the worldline effective field theory approach used to define their tidal deformability.

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