Theoretical Particle Physics

Superstrings and Quantum Gravity

A search for a quantum theory of gravity has for many years proved extremely difficult with superstring theory offering the only viable candidate. However in recent years it has been suggested that the problems in desribing gravity at high energy can be resolved using the renormalisation group equation.

Superstring theory

As well as offering a quantum theory of gravity superstring theory offers a potential framework for the unification of all particles and interactions. We devote a great deal of time and effort to the study of different aspects of string theory, with particular emphasis on working out different possible compactifications of M-theory, in the context of Supergravity, down to the four space-time dimensions we live in. This usually implies conducting technically involved calculations. We also look at the resulting phenomenology and cosmology. This implies considering topics such as moduli stabilization, supersymmetry breaking and the role of D-branes in order to get down to the Standard Model of Particle Physics. Here we combine detailed analytic calculations with algebraic and graphical support from different software packages. As string and M-theory are candidates for the fundamental theory, we continually seek ways of relating them to our other work.

Quantum Gravity

Our group is also interested in the physics of quantum gravity. In recent years, renormalisation group studies have indicated that a quantum theory of gravity in the metric field may be asyptotically safe, opening a new and exciting field of research. At very large distances, the renormalisation group modifications to the laws of gravity are studied in view of cosmological implications.

Quantum Gravity at the LHC

Much interest has recently been made to the possibility of large extra spatial dimensions which could lower the scale at which gravity acts. This could result in observable signals in futures high energy experiments such as the LHC such as the production of gravitons or quantum black holes.

Related members

David Bailin, Xavier Calmet, Daniel Litim