I’m an Associate Professor and Royal Society University Research Fellow at UCL.

I'm also deputy director of the Cosmoparticle Initiative. Previously I held fellowships in Oxford and Cambridge. I currently teach fourth year cosmology at UCL and am also highly active in public engagement. And I'm the author of some widely used scientific software. You can download my CV here.



My research group works to understand structure formation in the cosmos.

We especially focus on connecting the galaxies and overarching large scale structure observed by telescopes today with fundamental physics — such as the nature of dark matter, dark energy, and processes in the very early Universe.

To build a better understanding of these mysterious aspects of our cosmos requires a combination of statistical insight, numerical simulations and dynamical analyses. In the past, I've worked on a wide range of areas from measuring the large-scale uniformity of the Universe to modelling the dynamics of dwarf galaxies.

Recent work includes the development of ‘genetically modified’ simulations, which allow systematic exploration of the relationship between galaxies’ histories and their current properties. In particular one can examine how galaxy mergers and accretion interact with explosive supernovae and active galactic nuclei, determining the nature of the galaxies see. At the moment we’re applying the techniques to galaxies on all scales from the smallest dwarfs to the largest clusters.

Related approaches are allowing us to accelerate and improve the simulation of large scale structure in the Universe. The results are being used both for direct comparison to data and to improve understanding of the dynamics of cosmic structure formation.

Find our papers on arXiv


I currently run Advanced Physical Cosmology (PHAS0086) for fourth year undergraduates and Masters students.

This course is open to people from UCL and other Colleges across London; it starts from the basics of general relativity and works up to a derivation of the major features in the cosmic microwave background and large scale structure.

Students can find all course materials on Moodle.

I am a Fellow of the Higher Education Academy. Previously, as a postgraduate and postdoc, I taught various maths and cosmology courses.

Outreach & Media

I regularly work with schools and science organisations to help bring the excitement of cosmology into STEM education.

You can find online archives of some of my work with organisations like the Royal Institution and TED-ED. I've presented for science festivals and media organisations including BBC Radio 4 and World Service, New Scientist and Guardian Live.


I am the primary author and maintainer of tangos and pynbody, codes for analysing the output from numerical simulations. Pynbody has now been acknowledged in 160 publications across multiple fields.


You can reach me by email, twitter or for code-related problems and queries, please open a github issue.