One-loop quantum gravitational backreaction on the local Hubble rate. (12th April 2019)

• Record Type: Journal Article
• Authors: Fröb, Markus B
• Is Part Of: Classical and quantum gravity. Volume 36:Number 9(2019:May)
• Publication Date: 2019-04-12
• Subjects: perturbative quantum gravity -- invariant observables -- Hubble rate; Quantum gravity -- Periodicals; Gravitation -- Periodicals; Relativity (Physics) -- Periodicals; Space and time -- Periodicals; Periodicals; 521.1
• DOI: 10.1088/1361-6382/ab10fb
• Languages: English
• ISSNs: 0264-9381

Abstract

Abstract: We determine corrections to the Hubble rate due to graviton loops in a cosmological background spacetime of constant deceleration parameter. The corrections are gauge-invariant, based on a recent proposal for all-order gauge-invariant observables in perturbative quantum gravity. We find explicit expressions for the cases of matter- and radiation-dominated eras and slow-roll inflation with vanishing second slow-roll parameter. Interestingly, in the latter case the corrections can be described by a quantum-corrected first slow-roll parameter, which brings the spacetime closer to de Sitter space.