Institute for Advanced Study Informal Astrophysics Seminar

ABSTRACT: The problem of motion in General Relativity has lost its academic status since the new generation of gravitational wave detectors relies upon an accurate description of the dynamics of inspiralling compact binaries. The main difficulty in understanding such dynamics is rooted in the number of disparate scales involved, from the finite size of the bodies to the long wavelength gravitational modes which propagate out to the detector. Moreover, divergences occur due to approximations such as the point particle limit. Using effective field theory (EFT) techniques, in recent years a new approach has emerged which properly factorizes all the relevant degrees of freedom in the problem, while providing a very natural setup to handle divergences via textbook regularization/renormalization procedures. In the talk I'll review the basic ideas and results of the EFT framework. Our methods have already reproduced most of the results computed within more traditional Post-Newtonian (PN) approaches, as well as new results such as all the necessary ingredients to obtain the spin contributions to the energy flux and phase evolution to 3PN order. The EFT approach is therefore significantly more efficient than the standard PN computations, since it maps complex integrals into the computation of Feynman diagrams and allows for the same type of systematization as those commonly used in particle physics.