I carry our research in theoretical particle physics - the study of the fundamental particles which everything is made of and their interactions. Currently, particle physicists have a good theory (the "Standard Model") which describes the strong weak and electromagnetic forces. Gravity remains a force for which no satisfactory quantum theory exists. At present, the best candidate for a theory of gravity is "String Theory". This is a quantum theory where the fundamental objects are one dimensional (little strings!) rather than point like. Different vibrational modes (like sounds of a guitar string) correspond to different particles. To make sense the size of the string must be very small. Although very appealing, string theory has a number of problems (not least of which is it's very complicated mathematics) including its embarrassing desire to live in dimensions much larger than three (plus time). To be mathematically consistent it appears at first glance that string theory must be formulated in nine dimensions (plus time).

My own Research interests are focussed on various aspects of string theory and quantum gravity: Firstly I am interested in the process whereby string theory connects to low energy quantum gravity and four dimensional space-time. A key ingrediant on this connection is the "Effective action" which embodies the corrections of string theory to low energy behavious and also reflects the effects present in quantum gravity with increasing energy. In a slightly orthogonal approach I am interested in examining the renormalisability of quantum gravity and Ysng-Mills theories. In this we aim to determine if quantum (super) gravity theories are non-renormalisable and search for patterns and possible simplifying cases in the renormalised lagrangian. A highlight of this approach was , together with my collaborators finding the ``first hard evidence that a four dimensional supergravity theory is ultra-violet divergent''. I am also (partly by neccessity) interested in the mathematical process of pertubation theory and in streamlining calculations within pertubation theory.

A list of my research papers may be obtained from spires.

Some talks at conferences include