Waveforms for Extreme Mass Ratio Inspirals

The breakthrough detection of Gravitational Waves (GWs) by the LIGO-Virgo-KAGRA Collaboration (LVK) is generating waves of excitement within the physics community. The detection itself led to the award of the 2017 Nobel Prize in Physics. Even more exciting is that the first detection was only the start. LVK continues to make groundbreaking discoveries as the detector is tuned to be sensitive to ever more distant sources.The next quantum leap in GW science will come with the launch of the Laser Interferometer Space Antenna (LISA), recently adopted as a flagship European Space Agency L-class mission with support from NASA. Just as X-ray, gamma-ray and radio observations of the electromagnetic universe unveiled a host of sources which were previously undetectable by optical telescopes, the sensitivity of LISA to an entirely new GW frequency band will open the field up to a whole new realm of sources such as Extreme Mass-Ratio Inspirals (EMRIs), supermassive binaries, and exotic objects such as cosmic strings.LVK demonstrated that a hybrid approach is essential for GW science: experimentalists built the detector, while theoreticians produced models for the expected waveforms from GW sources. These waveforms form a crucial part of the data analysis pipeline; a matched-filtering approach is used to extract signals from noisy GW observations, and this process fundamentally relies on access to accurate waveform models. Without the models, many GW signals would go entirely undetected, and even those that are detected would be poorly understood.Many of the GW signals LISA will observe are qualitatively very different from those of LVK sources and will require fresh approaches to waveform modelling. Gravitational Self-Force (GSF) has long been established as the only viable approach for modelling highly asymmetric black hole binaries such as EMRIs, but no comprehensive, efficient and accurate GSF models yet exist. This project will, for the first time, build those models.