You Spin Me Round: Measuring Precession in the Black Hole Population

Lead Research Organisation: Cardiff University
Department Name: School of Physics and Astronomy


Understanding the predictions of general relativity for the dynamic interactions of two black holes has been a long-standing unsolved problem in theoretical physics. By studying for a PhD investigating the last orbits and the merger of two black holes, these unsolved problems can be answered which would give insight into the study and detection of gravitational waves. Investigating a binary system is imperative due to its purer signal and vast amount of energy released as they merge. Developing a computer model which solves Einstein's equations for binary blackhole systems will allow us to construct precise gravitational waveforms which obeys the theory of general relativity.

These theoretical predictions of the waveforms are critical for progress to be made in the field of gravitational waves and theoretical astrophysics in general whereby the resulting waveforms can only be calculated through numerical simulations of Einstein's equations. Theorising the gravitational waveforms allows for adapted filters to be added to the weak gravitational wave signal detected by LIGO and consequent statistical analysis to be carried out. Without the numerical solutions to Einstein's equations, the gravitational wave signal is too weak to carry out analysis and even to detect that the signal has passed through the detector. This ground-breaking research will therefore enable insights into developing a technique for testing Einstein's theory and validating all corollaries as a consequence and without this research the field of gravitational waves will not have any significant progresses.

This project is achievable within the timescale. The first year will be used to understand background reading and current numerical codes, the second year will be used to analyse initial data for higher mass ratios and spins and the third year will use the code to study the details of ringdown waveforms, blackhole recoil and precession effects.

Listening to world leading academics, including LIGO spokeswoman Dr Gabriela Gonzalez, describe experimental results which match their theoretical models so accurately highlighted to me the importance of being at the forefront of science and contributing to a field which is potentially the biggest scientific breakthrough of our lifetime. It is this joy for understanding the underpinning of the universe that will no doubt propel me through the difficult times of pursuing a PhD. After successfully completing a PhD at Cardiff, my passion for theoretical astrophysics will propel me into a career in academia. I plan on carrying out postdoctoral research to gain further insight into the mathematical formalisation of gravitational waves. This will culminate in significant progresses in the field of cosmology, with publications describing consequent modifications to Einstein's theory of General Relativity.


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Studentship Projects

Project Reference Relationship Related To Start End Student Name
ST/N504002/1 01/10/2015 31/03/2021
1938553 Studentship ST/N504002/1 01/10/2017 31/03/2021 Charlie Hoy
ST/S505328/1 01/10/2018 30/09/2022
1938553 Studentship ST/S505328/1 01/10/2017 31/03/2021 Charlie Hoy
Description OzGrav Parameter Estimation
Amount $1,500 (AUD)
Organisation Australian Research Council 
Department Centre of Excellence for Gravitational Wave Discovery
Sector Public
Country Australia
Start 03/2019 
End 03/2019
Description LIGO Scientific Collaboration 
Organisation LIGO Scientific Collaboration
Country United States 
Sector Academic/University 
PI Contribution Contributing to LIGO scientific outputs, collaboration publications and collaborative code.
Collaborator Contribution Regular training and meetings.
Impact Detection of gravitational waves and consequently multiple published papers in physical journals.
Title PESummary 
Description The PESummary Python library provides tools for creating professional looking summary pages and a single complete meta file containing all information about the analysis allowing for complete reproducability for all sample generating codes. This package is designed for users who want an easy solution to visualize the contents of their data files and to distribute the contents to collaborators or the general public. As a result, this package is meant to be as easy-to-use as possible with self explanatory function and class names and extensive documentation to show how easy it is to use this Summary page builder. The code is hosted at . 
Type Of Technology Software 
Year Produced 2019 
Open Source License? Yes  
Impact Learnt Javascript, HTML, CSS languages and further enhanced my python knowledge.