Dr. Tristan Mc Loughlin

  Integrable systems   Mathematical Physics   Quantum field theory   Quantum gravity   STRING THEORY

Many of my research interests centre around the goal of developing a deeper understanding of the nonperturbative behaviour of strongly coupled gauge theories. Such theories underpin our modern description of a wide range of physical phenomena from the existence of protons and neutrons, due to confinement in quantum chromodynamics (QCD), to the fractional quantum Hall effect (FQHE) for strongly coupled electrons in two-dimensions. As these phenomena occur beyond the regime where standard perturbative approaches are applicable we have limited theoretical tools with which to develop any physical understanding and there remain a great number of profound open questions. One novel approach to these problems, which is at the heart of much of my research, is the remarkable duality between specific quantum theories of gravity, such as string theory, and gauge theories. The duality relates the weakly interacting regime of one theory to the strongly coupled regime of the dual theory. While this makes proving the duality rather difficult, it means that we can learn about strongly coupled gauge theories by considering weakly interacting string theories. Furthermore, and just as interesting, it implies we can study problems in quantum gravity through the analysis of gauge theories. A separate, but related, theme in my research has been the study of scattering amplitudes in gauge theories, including gravitational theories and, most recently, higher-spin theories. From a conceptual point of view amplitudes are interesting as gedanken experiments which can give insight into the underlying properties of a given theory. Ultimately we are looking to find a mathematical reformulation of gravity that makes the known symmetries manifest, that gives an efficient method for computation and, most optimistically, to find a useful holographic description of asymptotically flat space-times that would give a definition of quantum gravity in such spaces.