PhD Seminar: Precession in black hole binary systems: towards calibrating precessing phenomenological waveform models to numerical relativity

The upcoming 22 of Setember maria by Lluc Planas Llompart will hold a seminar titled: Precession in black hole binary systems: towards calibrating precessing phenomenological waveform models to numerical relativity. The Seminar will take place at SAL02 in the Antoni Maria Alcover i Sureda building (UIB).

Title: Precession in black hole binary systems: towards calibrating precessing phenomenological waveform models to numerical relativity
Author: Maria de Lluc Planas Llompar
Abstract: The increase in sensitivity and detector upgrades planned in the coming years will challenge waveform models and demand considerable improvements in accuracy, parameter space coverage, and computational efficiency. Binary systems of black holes in general relativity span a parameter space of 9 intrinsic parameters: two spin vectors, the mass ratio and two parameters associated with eccentricity. When the black hole spins are misaligned with the orbital angular momentum, the spins and orbital plane perform a precessing motion that leads to a complex modulation, especially for the amplitude of the signal. This phenomenon can be modelled using an approximate map between precessing signals in a co-precessing non-inertial frame and aligned-spin signals, which is referred to as the “twisting-up approximation”. The current (fourth) generation of phenomenological waveform models, IMRPhenomX and IMRPhenomT use this approach directly, without calibrating precession information to numerical relativity. To further improve the accuracy of waveform models, it is necessary to only use the twisting-up procedure as a framework where unknown pieces of information are calibrated to numerical relativity simulations. A first step has been taken recently by the Cardiff group, extending the frequency domain IMRPhenomD mode. My project focuses on the preliminary steps to perform a numerical calibration of the ringdown in the time domain. We used 1400 SXS precessing simulations to compute direct fits of the quasi-normal mode emission during the ringdown and investigated the incorporation of extreme mass ratio precessing waveforms and the Surrogate models into our calibration dataset.