The Asymptotic Safety Scenario in QG

[selfAdjoint]

I want to recommend the following paper to anyone who wants the spec up on Renormalization Group flows, fixed points, or asymptotic safety. The author is interested in reviving the functinal integral approach to QG, which was aboandoned when 't Hooft and Veltzman showed GR was nonrenomalizable in the 1970s, in the context of the possible asymptotic safety of GR. In the course of his discussion of the issues involved he gives a mini tutorial in the topics I listed above. Here is the "contact information" for the paper:

http://arxiv.org/PS_cache/gr-qc/pdf/0610/0610018.pdf

The Asymptotic Safety Scenario in Quantum Gravity
– An Introduction –
M. Niedermaier∗

Comments: 72p, 1 figure. Introduction to the subject based on several talks and conference contributions. An elaboration on the evidence (c) and (d) (see abstract) can be found in a forthcoming `Living Reviews in Relativity' article with M. Reuter

The asymptotic safety scenario in quantum gravity is reviewed, according to which a renormalizable quantum theory of the gravitational field is feasible which reconciles asymptotically safe couplings with unitarity.All presently known evidence is surveyed: (a) from the 2+\epsilon expansion,(b) from renormalizable higher derivative gravity theories and a `large N' expansion in the number of matter fields, (c) from the 2-Killing vector reduction, and (d) from truncated flow equations for the effective average action. Special emphasis is given to the role of perturbation theory as a guide to `asymptotic safety'. Further it is argued that as a consequence of the scenario the selfinteractions appear two-dimensional in the extreme ultraviolet. Two appendices discuss the distinct roles of the ultraviolet renormalization in perturbation theory and in the flow equation formalism.

 

[Chronos]

Thanks for that very interesting link, SA. Will take awhile to digest - some of it is over my head - but that's the kind of stuff that I like. I don't seem to benefit from papers that do not require any effort to understand.

 

[Entropia]

Thank you for sharing this paper on the Asymptotic Safety Scenario in Quantum Gravity (QG). This is an interesting and timely topic in the field of theoretical physics. As the author mentions, the idea of asymptotic safety in QG has gained attention in recent years as a potential solution to the nonrenormalizability of General Relativity (GR).

The paper provides a comprehensive overview of the evidence for the asymptotic safety scenario, including results from perturbation theory, renormalizable higher derivative gravity theories, and truncated flow equations. It also discusses the role of perturbation theory in guiding our understanding of asymptotic safety.

One of the key insights of this paper is the suggestion that self-interactions in QG may appear two-dimensional in the extreme ultraviolet. This could have important implications for our understanding of the fundamental nature of space and time.

The author also highlights the importance of further research and investigation in this area, including the use of effective average action and the 2-Killing vector reduction. This paper serves as a valuable resource for anyone interested in learning more about the Asymptotic Safety Scenario in QG.

Overall, I highly recommend this paper to anyone interested in the topic of Renormalization Group flows, fixed points, or asymptotic safety in QG. It provides a thorough and accessible introduction to the subject and offers valuable insights for further research in this field.