Theoretical physics is a branch of physics that uses mathematical tools to try to understand the inner workings of nature. The current focus areas of the theoretical physics group are:
1. Classical and Quantum Gravity
The group works on problems ranging from classical to quantum gravity, with a current focus on the latter. A quantum theory of gravity must merge General Relativity with Quantum Theory, and has the potential of resolving some of the fundamental puzzles about our universe, like dark energy and the black hole information puzzle, as well as the singularities of General Relativity. Two different approaches to this problem are currently being pursued at RRI: (a) Loop Quantum Gravity which generalizes standard quantization techniques to a context in which there is no fixed spacetime geometry and hints at a discrete fine structure underlying the continuum classical theory of General Relativity, and (b) Causal Set Theory, where the causal structure of spacetime is quantized rather than the metric, giving rise to a fundamental spacetime discreteness which is nevertheless manifestly covariant and preserves local Lorentzian invariance.
2. Statistical Physics, Condensed matter, and Related Areas
The group works on diverse areas of equilibrium and nonequilibrium statistical physics of both classical and quantum systems. The areas of current focus include stochastic processes, active matter systems, soft and hard condensed matter, atomic and optical systems, quantum information, and open quantum systems. Members are actively pursuing problems related to active particle dynamics, nonequilibrium fluctuations, statistics of extreme and rare events, large deviation theory, random search processes, driven inelastic gasses, bio-polymers, quantum diffusion, quantum transport, thermalization and chaos, relation between topology and nonequilibrium dynamics, waveguide quantum electrodynamics, and spin noise spectroscopy. Some members are also involved in experimental collaborations both within and outside the institute.