Inflation in a scale-invariant universe
A scale-invariant universe can have a period of accelerated expansion at early times: inflation. We use a frame-invariant approach to calculate inflationary observables in a scale-invariant theory of gravity involving two scalar fields: the spectral indices, the tensor-to-scalar ratio, the level of isocurvature modes, and non-Gaussianity. We show that scale symmetry leads to an exact cancellation of isocurvature modes and that, in the scale symmetry–broken phase, this theory is well described by a single scalar-field theory. Lastly, ee find the predictions of this theory strongly compatible with current observations.
- Authors:
-
[1]
; [2]
; [3]
; [1]
- Univ. of Oxford, Oxford (United Kingdom)
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- ETH Zurich, Zurich (Switzerland)
- Publication Date:
- Report Number(s):
- FERMILAB-PUB-18-079-T; arXiv:1802.06069
Journal ID: ISSN 2470-0010; PRVDAQ; 1655609
- Grant/Contract Number:
- AC02-07CH11359
- Type:
- Accepted Manuscript
- Journal Name:
- Physical Review D
- Additional Journal Information:
- Journal Volume: 97; Journal Issue: 12; Journal ID: ISSN 2470-0010
- Publisher:
- American Physical Society (APS)
- Research Org:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Org:
- USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 79 ASTRONOMY AND ASTROPHYSICS
- OSTI Identifier:
- 1437397
- Alternate Identifier(s):
- OSTI ID: 1454351