PIRSA:05030112

Quantum gravity at astrophysical distances

APA

Reuter, M. (2005). Quantum gravity at astrophysical distances. Perimeter Institute for Theoretical Physics. https://pirsa.org/05030112

MLA

Reuter, Martin. Quantum gravity at astrophysical distances. Perimeter Institute for Theoretical Physics, Mar. 16, 2005, https://pirsa.org/05030112

BibTex

          @misc{ scivideos_PIRSA:05030112,
            doi = {10.48660/05030112},
            url = {https://pirsa.org/05030112},
            author = {Reuter, Martin},
            keywords = {Quantum Gravity, Particle Physics, Cosmology},
            language = {en},
            title = {Quantum gravity at astrophysical distances},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2005},
            month = {mar},
            note = {PIRSA:05030112 see, \url{https://scivideos.org/index.php/pirsa/05030112}}
          }
          

Martin Reuter Johannes Gutenberg University Mainz

Talk numberPIRSA:05030112
Source RepositoryPIRSA
Collection

Abstract

In this talk we assume that Quantum Einstein Gravity (QEG) is the correct theory of gravity on all length scales. We use both analytical results from nonperturbative renormalization group (RG) equations and experimental input in order to describe the special RG trajectory of QEG which is realized in Nature. We identify a regime of scales where gravitational physics is well described by classical General Relativity. Strong renormalization effects occur at both larger and smaller momentum scales. The former are related to the (conjectured) nonperturbative renormalizability of QEG. The latter lead to a growth of Newton's constant at large distances. We argue that this effect becomes visible at the scale of galaxies and could provide a solution to the astrophysical missing mass problem which does not require dark matter. A possible resolution of the cosmological constant problem is proposed by noting that all RG trajectories admitting a long classical regime automatically imply a small cosmological constant.