Scales and hierachies in asymptotically safe quantum gravity: a review

Abstract

The asymptotic safety program strives for a consistent description of gravity as a non-perturbatively renormalizable quantum field theory. In this framework the gravitational interactions are encoded in a renormalization group flow connecting the quantum gravity regime at trans-Planckian scales to observable low-energy physics. Our proceedings reviews the key elements underlying the predictive power of the construction and summarizes the state-of-the-art in determining its free parameters. The explicit construction of a realistic renormalization group trajectory describing our world shows that the flow dynamically generates two scales: the Planck scale where Newton's coupling becomes constant and a terrestrial scale where the cosmological constant freezes out. We also review the perspectives of determining the free parameters of the theory through cosmological observations.

18 pages, 5 figures. Prepared for submission to Foundations of Physics: S.I.: Naturalness, Hierarchy, and Fine-Tuning

References in corpus (7)

• Ultraviolet properties of f(R)-Gravity
• On the renormalization group flow of f(R)-gravity
• Cosmological perturbations and structure formation in nonlocal infrared modifications of general relativity
• Taming perturbative divergences in asymptotically safe gravity
• The Nonperturbative Quantum de Sitter Universe
• Lectures on the Cosmological Constant Problem
• RG flows of Quantum Einstein Gravity in the linear-geometric approximation