Post-Newtonian Gravitational Dynamics from Effective Field Theory

Abstract: Gravitational wave astronomy is rapidly maturing into a standard tool to study astrophysics, astronomy, and cosmology. Understanding the evolution and mergers of compact object binaries, an important source of gravitational waves, is essential to interpreting signals from modern gravitational wave observatories such as LIGO. In this thesis, we present progress towards computing the dynamics of binary systems during the early stages of binary mergers known as the inspiral phase. During this stage of a binary merger, there is a separation of scales between the compact object size, the orbital separation, and the radiation wavelength that lends itself to an effective field theory description, known as nonrelativistic general relativity. In this approach, we use velocity as the power-counting parameter of a post-Newtonian expansion to study these objects in a systematic way. In particular, we first study subleading spin effects in the equations of motion, the adiabatically conserved quantities of the system, and the radiative flux-balance equations to ultimately compute the accumulated orbital phase observable. We then compute the state-of-the-art next-to-next-to-leading order radiation reaction equations of motion from first principles. We perform important consistency checks for our results, and compare when possible, with the literature.

Research Advisor: Dr. Adam Leibovich