I am Professor of Cosmology at the Institute of Cosmology and Gravitation where I lead a team investigating the physics of the very early universe, a fraction of a second after the Big Bang, and the origin of cosmic structure.

All the structure that we see around us in the Universe today is thought to have originated from quantum fluctuations at ultra-high energies at early times. I study how the patterns of large-scale structure that we observe in the cosmos today can tell us about the physics at work close to the beginning of the Universe.

I also study primordial gravitational waves, relativistic effects in large-scale structure formation, dark energy and the late-time acceleration of our present Universe.

I am a fellow of the International Society for General Relativity and Gravitation, the Royal Astronomical Society and the Institute of Physics.

I am a board member of the Gravitational Physics Division of the European Physical Society and a member of the Particle Data Group collaboration that produces the Review of Particle Physics. I am also a member of the editorial board for the Philosophical Transactions of the Royal Society A, the world's first and longest-running scientific journal.


I studied natural sciences (physics) and maths at the University of Cambridge, and then went to the Astronomy Centre at the University of Sussex, where I obtained my DPhil in 1993.

I joined the University of Portsmouth in 1996 and was awarded a Royal Society University Research Fellowship in 1999, before being promoted to professor in the newly formed Institute of Cosmology and Gravitation in 2002.

In 2010 I became Director of the ICG, jointly with Prof Bob Nichol, and was head of the institute for 10 years before stepping down in July 2020.

I have published over 150 scientific papers in international journals and given talks on five continents.

In 2010 I spent 3 months as a visiting professor at Kyoto University in Japan and led a team which was awarded the Daiwa-Adrian prize for UK-Japan scientific collaboration.

In December 2019 I was chair of the local organising committee for the 30th Texas Symposium on Relativistic Astrophysics, one of the largest astrophysics conferences held every two years, bringing leading scientists from around the world to Portsmouth.

Research interests

I study models of the very early universe and the origin of structure in our Universe.

I have worked on inflationary models where variations in the primordial distribution of radiation and matter on very large scales can arise from quantum fluctuations on very small scales. I have also studied alternative proposals for the origin of structure, including pre-big bang and ekpyrotic models.

Much of my current work is devoted to understanding the non-linear  evolution of cosmological perturbations and how non-linear effects may be observed in current and future data.

Teaching responsibilities

I teach on the BSc and MPhys courses in Physics, and Physics, Astrophysics and Cosmology. I am currently module coordinator for a 4th year module in Contemporary Theoretical Physics and I also lecture on the 3rd year module on Physical Cosmology.