HET seminar: Gravitational waves from coalescing compact binaries: interfacing analytical and numerical approaches

Speaker: Alessandro Nagar

Title: Gravitational waves from coalescing compact binaries: interfacing analytical and numerical approaches

Abstract: The direct detection by the LIGO detectors of the gravitational waves emitted by coalescing black hole binaries (GW150914 and GW151226) has marked the beginning of gravitational wave (GW) astronomy. In the first part of the talk, I will briefly review the recent experimental result and remind the basics elements of gravitational wave theory, focusing on the qualitative structure of the GW signal emitted by a coalescing binary (either made by two black holes or two neutron stars).

In the second part of the talk, I will introduce the state-of-the-art analytical effective-one-body (EOB) approach to the eneral-relativistic two-body dynamics, its completion using numerical relativity (NR) simulations of (spinning) coalescing black hole binaries and its necessity to compute the (thousands of) analytical waveform templates needed for the actual data analysis of GW events like GW150914 and GW151226. Such theoretical interplay between analytical methods and numerical simulations is the key ingredient behind our interpretation of these events as a binary black hole coalescences.