Dynamics of compact objects in dense star clusters and implications for gravitational wave detections

The Ligo-Virgo interferometers have already detected 50 binary black hole mergers and hundreds to come. This new set of data will provide important clues to the properties of compact objects such as black holes and neutron stars and to the environments in which they form. The development of a theoretical understanding of the processes leading to compact object coalescence is required, which will enable to analyse and interpret the large number of new detections.

Merging compact-object binaries can form as the result of: (i) the evolution of massive binary stars in the field of a galaxy; and (ii) dynamical interactions in the secular evolution of star clusters. We will make the first precise prediction for scenario (ii), which we will compare to gravitational wave data from Ligo and Virgo to establish whether binary black hole mergers come predominantly from clusters or the galactic field.

The student will develop a numerical framework based on state-of-the-art software to make predictions for the gravitational waves produced by merging compact-objects in dense star clusters. By comparing the predictions of theoretical models to observations they will determine how the gravitational wave sources detected by LIGO-Virgo are formed.

Astrophysics has entered a new Golden Age. Advanced LIGO and VIRGO are operational; new detectors such as KAGRA and LIGO India will soon come online, and LISA will fly in 2030s. This project will provide a theoretical framework for the physical interpretation of this wealth of unprecedented new data.