Probing scalar-tensor theories with compact binaries

Until now, observations and experiments have confirmed General Relativity (GR) as the best theory of gravity. The current gravitational wave interferometers, LIGO and Virgo, as well as the future space-based detector LISA, will permit to challenge further GR in the highly dynamical and strong field regime of gravity. In this talk, I will focus on alternative theories with an additional scalar degree of freedom, in relation to compact objects. In particular, I will describe the evolution of compact binary systems in these theories using the post-Newtonian formalism. I will show that one of the most interesting phenomenological consequence lies in finite-size effects.