Keen to continue learning more astronomy and physics, I managed to gain a place on the one-year "Part III" of the Mathematics Tripos at Clare College and the Department of Applied Maths and Theoretical Physics at Cambridge (turning down an opportunity to start a PhD with John Peacock in Edinburgh!). A distinction in Part III enabled me to secure a studentship to read for a PhD at Cambridge's Institute of Astronomy. My PhD supervisors were Nick Kaiser and George Efstathiou. They guided me through a series of projects on galaxy clusters, gravitational lensing and galaxy formation which became the basis for my thesis, "The Evolution of Large Scale Structure and Galaxy Formation". The final year of my PhD was spent back in Oxford as George Efstathiou had moved from Cambridge to Oxford to take up the Savilian Chair of Astronomy, while Nick Kaiser had moved to the Canadian Institute of Theoretical Astronomy in Toronto. This was an important year in my life. Not only did I complete my PhD, but I also met Maggie, my wife to be. Soon after I took up a two year postdoctoral position at the University of California in Berkeley which I enjoyed greatly.
In 1991 Maggie and I moved to Durham, a small, beautiful medieval city in the North of England, where I was appointed to a combined postdoc and teaching position working with Carlos Frenk and Richard Ellis. Maggie and I were married the following year. Our children, Hannah and Daniel, were born there in 1993 and 1999 respectively. I have had various positions during my career in Durham. I was a PPARC Advanced Fellow from 1994 to 2001 when I was appointed to the Durham Physics department faculty. During this time I worked with my Durham colleagues on developing a useful analytic model of the way galaxies form and evolve through repeated mergers of small fragments over cosmic time. We used this model as a backbone for building the GALFORM computer code to model the formation of galaxies in a full cosmological setting. GALFORM is still widely used today. In 2005 I was promoted to Professor and from December 2019 to July 2025 I held the post of director of the Instutute for Computational Cosmology.
My involvement in the "2-degree galaxy redshift survey," the 2dFGRS, began when I joined a breakout meeting during a lunch break at the 1994 National Astronomy Meeting in Edinburgh. The meeting included Richard Ellis, John Peacock, George Efstathiou, Carlos Frenk and fellow former students of George, Will Sutherland and Steve Maddox whom I knew well from our Cambridge and Oxford days. This group soon grew into the 30 strong Anglo-Australian collaboration which designed and implemented the 2dFGRS utilizing the innovative 400 fibre robotic 2dF spectrographic instrument on the Anglo-Australian Telescope (AAT). The then unique ability of this instrument to measure 400 galaxy spectra simultaneously and the pre-existing "APM galaxy catalogue," produced by Steve Maddox, George Efstathiou, Will Sutherland and Jon Loveday enabled us to measure 220,000 galaxy redshifts between 1995 and 2002. The resulting 3-dimensional map of the large scale galaxy distribution was 10 times larger than pre-existing surveys -- though it was soon to be overhauled by the Sloan Digital Sky Survey. The 2dFGRS team was a wonderfully productive collaboration. Innovative analysis lead by a wide range of team members lead to a stream of important results that pushed the study of the largest scale structure of the Universe to a new level. In 2015, I became involved in the DESI survey -- a next generation sucessor to 2dFRGS and SDSS. Within DESI, I co-led the Bright Galaxy Survey working group from 2015 to 2019, the Cosmological Simulations working group in 2019 and was co-chair of the membership committee (2022 to 2025). The large dedicated team of scientists in DESI have turned the BAO "cosmic yardstick" into a precise tool for measuring the expansion history of the universe and the evolution of Dark Energy.
Throughout my time at Durham I have enjoyed the mentorship of my colleague Carlos Frenk. Together we have worked on numerous projects and jointly supervised many excellent PhD students. When I started in Durham the theory group lead by him consisted of just two students and two postdocs. I have had the pleasure of seeing the steady growth of the group which came of age with the founding of the Institute for Computational Cosmology (ICC), housed in the Ogden Centre for Fundamental Physics in 2002. The institute has continued to expand and has now outgrown the original Ogden building. In November 2016 the group moved into an iconic new building designed by the internationally renowned architect Daniel Libeskind.