# Professor Tim Morris

Prof Tim R. Morris is professor of theoretical physics, Fellow of the Institute of Physics, Fellow of the Higher Education Academy, and Head of the Theoretical High Energy Physics theory group, one of the largest groups in the UK. He has previously been both head and deputy head of department. For the year 2017/18, Tim has a Royal Society Leverhulme Trust Senior Fellowship, devoted full time to research into the Wilsonian renormalization group in quantum gravity. His recent work on asymptotic safety solved for the first time the fixed point structure in the infinite dimensional $f(R)$ approximation. He has led in developing these approximations in particular in the large curvature domain. He has begun the development of a manifestly diffeomorphism invariant and background independent formalism. His work is demonstrating that there is much more to the renormalization group properties of quantum gravity than has been assumed.

Tim's very first research was in Quantum Chemistry whilst he was still at school, and later when he was a Scholar at Cambridge University. His PhD research was on Instantons in Super Yang-Mills, at Southampton. In 1985 he won a prestigious Harkness Fellowship to do post-doctoral research at Princeton, NJ USA. While there, he was amongst the first to apply Polyakov's new methods to open strings, and to work on Witten's string field theory. In 1987 he returned to a lectureship in Southampton. Following work at Fermilab on research leave in 1989, he discovered a way of using complex matrix models to formulate and solve various simple string theories non-perturbatively. In 1992 he won simultaneously both a CERN fellowship and SERC/PPARC Advanced Fellowship. During these fellowships, he developed the Wilsonian/exact renormalization group into a powerful methodology, both calculationally and conceptually. He discovered, independently the flow equation for the effective average action proposed by Wetterich a few months previously (which was in turn a rediscovery of the flow equation first introduced by Nicoll and Chang in 1977), proposed the derivative expansion (now established as one of the most powerful of approximation methods in this framework), showed how to solve for fixed points and quantised eigenoperators in these infinite dimensional approximations, and recover analytically the correct behaviour in terms of renormalised couplings. He developed a manifestly gauge invariant exact renormalization group, a long standing unsolved problem, which at the same time solved other long standing problems: continuum computations without gauge fixing, and furnishing a physical gauge invariant regulator.

Tim has worked on a number of other areas, including MHV rules, beyond the Standard Model, and cosmology, held a number of other grants and fellowships, and has had extensive experience at both the undergraduate and graduate level. He is an accomplished pianist; he obtained a diploma from the Royal Academy in 1980, won the audience prize in the Pianist-Yamaha competition for outstanding amateurs in 2005, and has performed several concertos.