Ultraviolet Divergences and Scale-Dependent Gravitational Couplings
Abstract
I review the field-theoretic renomalization group approach to quantum gravity, built around the existence of a non-trivial ultraviolet fixed point in four dimensions. I discuss the implications of such a fixed point, found in three largely unrelated non-perturbative approaches, and how it relates to the vacuum state of quantum gravity, and specifically to the running of $G$. One distinctive feature of the new fixed point is the emergence of a second genuinely non-perturbative scale, analogous to the scaling violation parameter in non-abelian gauge theories. I argue that it is natural to identify such a scale with the small observed cosmological constant, which in quantum gravity can arise as a non-perturbative vacuum condensate. (Plenary Talk, 12-th Marcel Grossmann Conference on Recent Developments in General Relativity, Astrophysics and Relativistic Field Theories, UNESCO Paris, July 12-18, 2009).
- Publication:
-
arXiv e-prints
- Pub Date:
- February 2010
- DOI:
- 10.48550/arXiv.1002.0813
- arXiv:
- arXiv:1002.0813
- Bibcode:
- 2010arXiv1002.0813H
- Keywords:
-
- High Energy Physics - Theory;
- General Relativity and Quantum Cosmology
- E-Print:
- 24 pages, 3 figures