Center for Relativistic Astrophysics (CRA) - Prof. Lionel London

Abstract

Since Einstein's quadrupole formalism, multipolar analysis has played a central role in gravitational wave theory. In particular, gravitational waves from compact sources are ubiquitously represented using spin weighted spherical harmonic multipoles. But there is good reason to expect that a more natural basis exists for representing gravitational waves from astrophysical systems with angular momentum. In this talk I will review the recent developments in gravitational wave signal models for binary black hole systems. A key limitation of many such models is that they do not account for the more natural “spheroidal” harmonic nature of the post-merger signal. In this regard, I will briefly discuss recent work at the interface of BH perturbation theory, and numerical relativity which uses spheroidal harmonic information from NR simulations to model the late post-merger for spinning but non-precessing binary black hole systems. Lastly, the spheroidal harmonics will be discussed as a potentially more appropriate basis for all of inspiral, merger and ringdown.