Abstract:

A key property that shapes the gravitational waveform of binary systems is the tidal deformability of their constituents, quantified by the Love numbers. In modern treatments of the gravitational two-body problem, the binary dynamics are described within an effective field theory (EFT), where Love numbers enter as Wilson coefficients encoding the finite-size response of each object. In this talk, I will introduce Shell Effective Field Theory, a new framework for computing the classical gravitational dynamics of compact objects, with particular emphasis on extracting Love numbers. By combining techniques from quantum field theory with solutions to black-hole perturbation theory, Shell EFT circumvents the loop integrations that constitute the main bottleneck in conventional approaches. I will present new results for dynamical Love numbers of generic compact objects through order G^9, corresponding to an eight-loop calculation, and conjecture their all-orders structure in the case of a Schwarzschild black hole.