# Quantum Gravity

Quantum gravity is the quest for a physical theory describing the gravitational interaction at all energy scales, thus unifying Einstein's general relativity, which describes gravity as the curvature and deformation of the space-time itself, and the quantum theory, which rules the microscopic dynamics of particles and their interactions. There are various approaches to this standing question for theoretical physics. The research work of our team focuses on "Spinfoam" models. These models provide us with a well-defined path integral formalism for quantum gravity. Sharing many common points with the Regge calculus for discretized general relativity, they allow to compute transition amplitudes between quantum geometry states and thus define a covariant framework for the canonical quantization scheme proposed by Loop Quantum Gravity. In this context, we are mostly interested in the construction, analysis and development of these spinfoam models, to the definition of study of their semi-classical regime in which we wish and should recover classical gravity and perturbative quantum corrections. In particular, a reformulation of spinfoam models in term of group field theory, which can be considered as generalized matrix models, allows a non-perturbative definition of the transition amplitudes and hints towards a deeper relation between these models and non-commutative geometry. We also work on the coupling between matter (particles and fields) to quantum gravity and on deriving effective theories describing the matter dynamics of the "deformed special relativity" type. Furthermore, other topics of interest are the study of quantum black holes, their entropy and thermodynamics, on the extraction of quantum gravity corrections to the cosmological dynamics and finally to the interface between quantum gravity, quantum information and quantum computing.

For more details on our research activities, our publications and our online seminar series, please visit our webpage: https://qglyon.wordpress.com/