Supervisor: Dr Bence Bécsy (Email b.becsy[at]bham.ac.uk)

The recent detection of a stochastic gravitational-wave background by pulsar timing arrays has opened a new window on the universe. Pulsar timing arrays probe gravitational waves at frequencies a billion times lower than LIGO, using millisecond pulsars as ultra-precise cosmic clocks. These signals are thought to originate from supermassive black hole binaries, pairs of black holes millions to billions of times the mass of the Sun, or potentially from the early universe, offering a glimpse of new physics.

This PhD project focuses on developing and applying advanced data analysis techniques to detect and characterize these low-frequency gravitational waves and use them to probe the astrophysical processes governing the formation and evolution of their sources.  The primary challenge is that many overlapping signals and noise processes are present in the data simultaneously, requiring sophisticated modelling to disentangle them. You will work at the cutting edge of statistical and computational methods, including signal and noise modelling, Bayesian inference, and GPU-accelerated programming, to extract meaningful astrophysical information from these complex datasets. Many of these techniques are directly transferable to other gravitational-wave experiments, such as the future space-based LISA detector, which will probe a complementary frequency range and target a wide variety of sources including massive black hole mergers, stellar-origin black hole binaries, galactic white dwarf binaries, and extreme mass ratio inspirals.

Supervisor: Dr Gregorio Carullo (Email g.carullo[at]bham.ac.uk)

Coalescences of two black holes are the most powerful cosmic events happening throughout the Universe. Their dynamics sources the strongest gravitational fields experimentally accessible, and gives rise to violent space-time deformations known as gravitational waves. The observation of gravitational waves by the large scale LIGO-Virgo interferometers on Earth has opened a golden era of strong-gravity exploration, powering the largest surge ever witnessed in gravity-related research worldwide. Despite rapid progress, many open questions still remain, as our understanding of the general-relativistic two-body problem is far from complete.

The PhD candidate will delve into strong-gravity research, and gain experience into both advanced modelling methods in General Relativity and cutting-edge statistical inference techniques deployed on large supercomputers, applied to gravitational wave signals detected by current earth-based observatories or upcoming space-based missions. Details of the project will be agreed with the candidate depending on their interests and inclinations, but specific examples of challenging problems on which the aforementioned skills could be used include: measuring yet unobserved black holes vibrational spectra, modelling the near-merger two-body dynamics, developing innovative inference techniques targeting highly eccentric binaries, or probing the nature of black hole event horizons.

Supervisor: Dr Geraint Pratten (Email g.pratten[at]bham.ac.uk)

Theoretical models for gravitational wave signals emitted by coalescing compact binaries are the cornerstone of modern gravitational wave astrophysics. Among the most pressing challenges for the next generation of models is the detailed treatment of spin precession and orbital eccentricity. These effects encode critical information about compact binary formation channels and evolutionary pathways, whilst their omission can introduce significant systematic biases in parameter estimation, detection pipelines, and tests of fundamental physics.

In this PhD project, you will develop a comprehensive framework for modelling gravitational wave signals from precessing eccentric compact binaries across the full detector landscape, from ground-based instruments such as LIGO and Virgo through to the space-based LISA observatory. The research will advance post-Newtonian waveform modelling through improved analytical techniques, incorporate strong-field information from numerical relativity simulations, and explore optimisation strategies for deploying these models in modern data analysis pipelines. You will have the opportunity to join the LIGO Scientific Collaboration as well as the team developing the scientific tools for LISA, a flagship European Space Agency mission.

Key objectives include incorporating higher-order post-Newtonian corrections, higher-order harmonics, and mode asymmetries, whilst exploring extensions to the merger-ringdown phase. The developed models will be validated against numerical relativity simulations and applied to real gravitational wave observations to constrain astrophysical formation scenarios and test fundamental physics. This work will provide essential tools for extracting science from current observing runs and preparing for next-generation gravitational wave detectors.

The PhD Student will be given the opportunity to work directly with gravitational-wave data and to play a role in the gravitational-wave discoveries made by the LIGO Scientific Collaboration.

Supervisor:Supervisor: Dr Patricia Schmidt (Email: P.Schmidt[at]@bham.ac.uk)

Gravitational waves from colliding neutron stars provide a unique opportunity for probing the properties of ultra-dense matter and fundamental interactions in extreme regimes. This PhD project focuses on modelling tidal effects in the waveforms emitted by binary neutron stars, and subsequently applying these models to parameter estimation and population inference, with an emphasis on determining the as-of-yet unknown neutron star equation of state (EOS).

The successful candidate will work to create cutting-edge models using post-Newtonian (PN) and numerical relativity techniques to better capture the complex physics of neutron star systems. They will then apply these models within a Bayesian inference framework to analyse gravitational-wave data, enabling new insights into the structure of neutron stars and EOS properties.

This project offers a unique opportunity to innovate in waveform modelling and conduct novel analyses of gravitational-wave observations. They will also be encouraged to join the LIGO Scientific Collaboration. Ideal applicants will have a strong background in theoretical astrophysics and general relativity, computational and analytical skills as well as core statistics knowledge.