GWsFromEMRIs · Gravitational waves from extreme mass-ratio inspirals

Gravitational waves from extreme mass-ratio inspirals

The goal of the GWFromEMRIs project was the computation of gravitational waveforms emitted by extreme mass-ratio-inspirals (EMRIs), one of LISA most-awaited sources. In an EMRI, a stellar-mass objects slowly fall towards a supermassive black hole, tracing tens of thousands of orbits around its companion. The long time spent in the LISA frequency band (months to years) will allow to explore the strong-field regime in unprecedented detail and to test the core laws of General Relativity. These systems can be successfully described within the gravitational-self-force formalism, which builds upon black-hole perturbation theory techniques to compute the orbital motion of the secondary mass. To this purpose, the project envisaged the development of new numerical tools to compute the self-force in Kerr spacetime. While this has been part of my research interests, the action has morphed into a more comprehensive and ambitious project, where I complemented numerical work on the computation of the gravitational self-force with an intense modelling effort within the LIGO collaboration. In particular, I was one of the core developers of a new family of waveform approximants for binary-black-hole coalescences (Pratten et al. Phys. Rev. D 102, 064001, 2020, García-Quirós, Colleoni et al. Phys. Rev. D 102, 064002, 2020) spanning a large region in parameter space, extending from extreme-mass-ratio to comparable-mass binaries. The main application of these models is in data analysis for ground-based interferometry, but they could be useful for preliminary parameter estimation studies for LISA. The main motivation behind this shift of focus was the start of LIGO’s observing run (O3). O3 called for renewed efforts to deliver a new generation of black-hole binary waveform models that could meet the requirements of increasingly challenging data-analysis campaigns. In preparation for new and possibly exceptional detections, much work was devoted to the construction of templates going beyond the quadrupole-mode approximation, which had been the basis for previous parameter estimation studies. This development was pushed also by a fresh injection of numerical relativity data (Class. Quantum Grav. 36, 195006, 2019), on which modern waveform models rely to construct a faithful representation of the signal. Although the models developed during the project are not specifically targeting EMRIs, they are flexible enough to incorporate self-force information once this becomes available.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз