I will show how to derive analytic gravitational waveforms associated to the coalescence of a “hairy” black hole binary in Einstein-scalar-Gauss-Bonnet gravity (ESGB). To this aim, I will first present the post-newtonian (PN) lagrangian and gravitational wave fluxes. I will then extend the scope of the PN approximation to the strong field regime near merger by generalizing the effective-one-body (EOB) formalism to ESGB gravity. In light of the first law of thermodynamics, I will also show that inspiralling black holes are described by sequences of constant Wald entropy equilibrium configurations. As a consequence, they can progressively grow scalar “hair” until they turn into naked singularities.
