Daniel Litim

General relativity is acknowledged as the classical theory of gravitational interactions, applicable far above the Planck length. The quantisation of general relativity remains an open problem. It has been suggested that gravity may be non-perturbatively renormalisable, an "asymptotic safety" scenario which requires the existence of an ultraviolet fixed point. We study Euclidean quantum gravity with renormalisation group (RG) methods in the Einstein-Hilbert truncation. Analytical results for a non-trivial ultraviolet fixed point are found. We discuss the universal behaviour of the RG flow for the gravitational coupling and the cosmological constant. In d=4 dimensions, and at the ultraviolet fixed point, we compare our results with lattice simulations within simplicial gravity. In the infrared limit, results are compared with findings from loop computations.

Seminario de Física Atómica, Molecular y Celular, Facultad de Ciencias, 1rd Floor, Universidad de Zaragoza