Imperial College London
The physical theory that describes the behaviour of particles and waves -- how they interact, are created and destroyed -- is quantum field theory. It describes fundamental particles, such as photons (the particles that constitute the electromagnetic radiation), the electrons in a metal, and all sorts of exotic objects produced at particle accelerators; but it also describes ``effective" particles, such as the vibration waves in crystals or the small magnetic vortices in superconductors. Being so universal, it describes a variety of systems and phenomena: from metals, superconductors and more exotic materials, to nuclear reactions in the stars and even the birth of the universe.
Many systems can be described in terms of particles that are interacting just weakly, and we understand those systems very well. Conversely, when the interaction is strong we are lost, as the particles behave completely differently from how they would if they were alone. Still, there are in nature lots of physical phenomena governed by strong coupling, such as the quarks inside the atomic nuclei, the high-temperature superconductors and many more. All these systems cry out for alternative approaches.
The core of my research activity is about the development of a new technique to deal with strong coupling, called ``localisation". It is a sophisticated and extremely powerful mathematical tool, which allows us to perform computations that were not possible before. This has potential repercussions on many areas: particle physics, condensed matter, astrophysics and cosmology -- even finance, one could speculate!
Besides, I investigate applications of those new methods to concrete physical problems. One area we have recently stumbled upon is quantum gravity! According to string theory, one can understand quantum phenomena in general relativity by studying a quantum field theory at the boundary of spacetime. Thus, for instance, we can use localisation to learn about properties of black holes.
Interests and expertise (Subject groups)