[STFC Studentship] Simulation-based Inference of gravitational waves signals from black holes and neutron stars

Black holes and neutron stars are the densest objects in the universe, well beyond what we can produce in a laboratory and at the very edge of our understanding of physics. They lead to puzzling physical consequences, in particular regarding the behaviour of space and time. When they collide, they produce the most violent events in the universe, shaking space and time and creating gravitational waves: ripples in the fabric of spacetime which propagate away at the speed of light. Gravitational-waves were observed for the very first time in September 2015, when two colliding black holes were detected by the LIGO-Virgo collaboration. Since then, hundreds of signals have been observed, and we have been able to characterise the black holes and neutron stars at the source of those gravitational waves.

This characterisation currently involves stochastic sampling methods with a very high computational cost, and simplified assumptions of the detectors’ properties. This project will leverage modern advances in likelihood-free inference methods, and in particular simulation-based inference, to solve this inference problem accurately. Our approach will adapt automatically to changing features in the detector noise, allow for new data to be continuously included, and will be applicable to the upcoming new generation of gravitational-wave detectors.

Gravitational-wave sources are laboratories where in neutron stars we can measure the equation of state of matter at densities otherwise unattainable, and test General Relativity in the strong field regime. Inference of the extragalactic population of gravitational-wave sources enables new understandings of the Universe’s structure of matter, and independent measurements of its expansion.

The typical academic requirement is a minimum of a 2:1 physics and astronomy or a relevant discipline. 

Applicants whose first language is not English are normally expected to meet the minimum University requirements (e.g. IELTS 6.5 Overall with 5.5 minimum in sub-scores) (https://www.cardiff.ac.uk/study/international/english-language-requirements) 

How to apply 

Applicants should apply to the Doctor of Philosophy in Physics and Astronomy with a start date of 1st October 2025. 

Applicants should submit an application for postgraduate study via the Cardiff University webpages (https://www.cardiff.ac.uk/study/postgraduate/research/programmes/programme/physics-and-astronomy) including: 

• your academic CV 

• Your degree certificates and transcripts to date including certified translations if these are not in English 

• a personal statement/covering letter 

• two references, at least one of which should be academic. Your references can be emailed by the referee to physics-admissions@cardiff.ac.uk  

Please note: We are do not contact referees directly for references for each applicant due to the volume of applications we receive.     

In the "Research Proposal" section of your application, please specify the project title and supervisors of this project. You can apply for up to three of our advertised STFC projects by listing them in order of preference in the free text area of the "Research Proposal" section of the online application form. 

In the funding section, please select that you will not be self-funding and write that the source of funding will be STFC. 

Once the deadline for applications has passed, we will review your application and advise you within a few weeks if you have been shortlisted for an interview. 

Cardiff University and the School of Physics and Astronomy are committed to supporting and promoting equality and diversity. Our inclusive environment welcomes applications from talented people from diverse backgrounds. We strongly welcome female applicants and those from any ethnic minority group, as they are underrepresented in our School. The School of Physics & Astronomy has a Juno Practitioner accreditation that recognises good employment practice and a commitment to develop the careers of women working in science. The University is committed to ensuring that we sustain a positive working environment for all staff to flourish and achieve. As part of this commitment, the University has developed a flexible and responsive framework of procedures to support staff in managing their work and personal commitments wherever possible. Applications are welcome from individuals who wish to work part-time or full time. 

Cardiff University is a signatory to the San Francisco Declaration on Research Assessment (DORA), which means that in hiring and promotion decisions we will evaluate applicants on the quality of their research, not publication metrics or the identity of the journal in which the research is published. More information is available at: Responsible research assessment - research – Cardiff University. 

Applications may be submitted in Welsh, and an application submitted in Welsh will not be treated less favourably than an application submitted in English.  We very much welcome applications in Welsh.