Safe beginning for the Universe?
File(s)
Published version
Author(s)
Lehners, Jean-Luc
Stelle, KS
Type
Journal Article
Abstract
When general relativity is augmented by quadratic gravity terms, it becomes a renormalizable theory of gravity. This theory may admit a non-Gaussian fixed point as envisaged in the asymptotic safety program, rendering the theory trustworthy to energies up to the Planck scale and even beyond. We show that requiring physical solutions to have a finite action imposes a strong selection on big-bang-type universes. More precisely, we find that, in the approach to zero volume, both anisotropies and inhomogeneities are suppressed while the scale factor is required to undergo accelerated expansion. This provides initial conditions which are favorable to the onset of an inflationary phase while also providing a suitable starting point for the second law of thermodynamics in the spirit of the Weyl curvature hypothesis.
Date Issued
2019-10-29
Date Acceptance
2019-10-09
Citation
Physical Review D: Particles, Fields, Gravitation and Cosmology, 2019, 100 (8)
ISSN
1550-2368
Publisher
American Physical Society
Journal / Book Title
Physical Review D: Particles, Fields, Gravitation and Cosmology
Volume
100
Issue
8
Copyright Statement
© 2019 The Author(s). Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Sponsor
Science and Technology Facilities Council (STFC)
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000493487900003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
ST/P000762/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
Physics, Particles & Fields
Physics
INFLATIONARY UNIVERSE
ASYMPTOTIC SAFETY
FLATNESS
HORIZON
GRAVITY
Publication Status
Published
Article Number
ARTN 083540
Date Publish Online
2019-10-29