I am a Senior Research Fellow and Senior Lecturer at the Institute of Cosmology and Gravitation. I am an observational cosmologist – this means I study the properties of dark energy, dark matter and gravity using data on the large-scale structure of the Universe gathered by galaxy surveys performed on the world’s leading telescopes.

My research is funded by the Science and Technology Facilities Council (STFC) and previously by the European Commission.

Research interests

My research covers theory, simulation and observational cosmology, with a focus on methods of analysing galaxy survey data to obtain cosmological information. I use a combination of many techniques to achieve this, including redshift-space distortions, baryon acoustic oscillations, gravitational lensing and secondary CMB anisotropies. I am particularly interested in the use of new cosmological probes beyond two-point clustering statistics, including low-density regions identified in 3D maps of the galaxy distribution known as cosmic voids to enhance the effectiveness of all these analyses. I also work on models of decaying dark matter and inflation in the early Universe. 

I am heavily involved in the Dark Energy Spectroscopic Instrument (DESI) survey that is mapping the positions of over 30 million galaxies, and I co-lead the Galaxy and Quasar Clustering working group in the collaboration.

Another large part of my work is within the Euclid satellite mission mapping galaxies from space. I lead an Internal Data work package responsible for creating spectroscopic galaxy catalogues and the visibility mask, and co-lead a work package on voids. I am the Portsmouth PI for a UK Space Agency grant funding UK contributions to the Euclid Science Ground Segment infrastructure development.

In the past I also worked on the extended Baryon Oscillation Spectroscopic Survey (eBOSS) and the Dark Energy Survey (DES).