Research Groups

Research Groups

Things happen in the universe outside that cannot occur on our tiny planet. Most `ordinary’ matter (as distinct from dark matter and dark energy) is governed by much longer-range forces than the matter with which we are familiar: stars and galaxies interact by gravity, the longest-range force of all, and most gas in stars and between them is ionised and the ions and free electrons have long-range electromagnetic interactions.   

 

Within the astro-plasma group James Binney and John Magorrian work mostly on the structure and evolution of galaxies, especially our own, which is currently the subject of massive international surveys. Their aim is to understand how our Galaxy is constructed, works as a machine, and how it evolved to its present state. Michael Barnes and Felix Parra focus on magnetically confined plasmas, mastery of which is the key to extracting an essentially limitless supply of carbon-free energy from sea water by reproducing on Earth the process that heats the Sun. Alex Schekochihin works on both fusion and astrophysical plasmas, such as the incredibly rarefied plasma that fills intergalactic space and contains the majority of all ordinary matter. A common theme running through the astro-plasma group is the kinetic theory of particles that interact mainly through a fluctuating macroscopic mean field.

Modern condensed matter physics is concerned with systems of strongly correlated particles in an enormous variety of settings. These particles range from electrons in solids to biological cells, but a common theme is the emergence of complex collective behaviour. Some of the systems of interest are inherently quantum-coherent, while in soft and biological matter classical statistical descriptions apply.

 

Historically, quantum states of matter such as superconductors or ferromagnets have been classified using symmetry principles. Over the last decade the discovery of new types of matter, such as topological insulators and non-equilibrium steady states in cold atomic gases has made it clear that this classification is insufficient. The overarching theme of the work by John Chalker, Fabian Essler, Paul Fendley and Steve Simon is the characterisation and understanding of states of quantum matter that defy conventional classification themes. Ramin Golestanian, Ard Louis, and Julia Yeomans study the physics of living matter. They address current ideas surrounding various forms of active matter - such as cells and microorganisms - and discuss how these systems naturally provide a testing ground for theories of non-equilibrium statistical physics, as well as how evolution finds solutions in hyper-astronomically large search spaces to design living matter.

Particle theory is concerned with the fundamental nature of matter and forces in the universe, seeking to explain why the world is the way it is. Its triumph is the Standard Model – a relativistic quantum field theory of all the known interactions except gravity – which successfully explains all microphysical processes observed in the laboratory. However it does not account for the gross features of the Universe – the asymmetry between matter and antimatter, the dominance of dark over luminous matter, the inhomogeneities that have grown to create the observed large-scale structure – all of which require new physics.

In our group Fabrizio Caola, Lucian Harlnad-Lang, Gavin Salam and Lorenzo Tancredi use quantum chromodynamics to compute processes that occur in the Large Hadron Collider at CERN, while Prateek Agrawal, Joe Conlon, John March-Russell and Subir Sarkar all work on physics beyond the Standard Model and its implications for colliders as well as astrophysics & cosmology. Andre Lukas seeks string theories that are consistent with the Standard Model, John Wheater investigates discretised models of quantum gravity and Andrei Starinets explores the AdS/CFT correspondence between general relativity and quantum field theory. We enjoy close links with our experimental colleagues in Particle Physics, as well as with mathematical physicists in the Maths Institute.