Gravity, Quantum Geometry and Field Theory Unit (Reiko Toriumi)
The Gravity, Quantum Geometry and Field Theory Unit's research interest lies in quantum gravity. Quantizing gravity has been one of the most difficult problems in physics. There have been many approaches to quantizing gravity, which have given us mathematically and physically interesting ideas, such as the unification of forces, the emergence of spacetime, the problem of time, information paradox, spacetime foam, non-commutativity of spacetime, extra-dimensions like in Calabi-Yau manifold, duality, holography, etc.
Geometry, which initially found a link to gravity by Einstein's proposal, namely General Relativity, has also been playing a major role in the studies of quantum gravity. Geometrical aspects of gravity have been enjoyed by the advancement in the approaches to quantum gravity, such as matrix models, tensor models, lattice methods like causal dynamical triangulations and Regge calculus, etc.
Quantum field theory (QFT), which gave us a tremendous success in describing the Standard Model including the weak, the strong and the electromagnetic forces, is also a central solid modern tool in describing physical systems with many degrees of freedom. QFT lets us explore critical phenomena and the scale dependence of the physics through the renormalization group.
We combine these advanced tools in order to reveal the quantum nature of spacetime.