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Frame-covariant formulation of inflation in Scalar-Curvature theories

Burns, Daniel, Karamitsos, Sotirios and Pilaftsis, Apostolos (2016) Frame-covariant formulation of inflation in Scalar-Curvature theories. Nuclear Physics B, 907, 785-819.

Record type: Article

Abstract

We develop a frame-covariant formulation of inflation in the slow-roll approximation by generalizing the inflationary attractor solution for scalar-curvature theories. Our formulation gives rise to new generalized forms for the potential slow-roll parameters, which enable us to examine the effect of conformal transformations and inflaton reparameterizations in scalar-curvature theories. We find that cosmological observables, such as the power spectrum, the spectral indices and their runnings, can be expressed in a concise manner in terms of the generalized potential slow-roll parameters which depend on the scalar-curvature coupling function, the inflaton wavefunction, and the inflaton potential. We show how the cosmological observables of inflation are frame-invariant in this generalized potential slow-roll formalism, as long as the end-of-inflation condition is appropriately extended to become frame-invariant as well. We then apply our formalism to specific scenarios, such as the induced gravity inflation, Higgs inflation and $F(R)$ models of inflation, and obtain more accurate results, without making additional approximations to the potential. Our results are shown to be consistent to lowest order with those presented in the literature. Finally, we outline how our frame-covariant formalism can be naturally extended beyond the tree-level approximation, within the framework of the Vilkovisky--DeWitt effective action.

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1603.03730v3 - Accepted Manuscript
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1-s2.0-S0550321316300748-main - Version of Record

Accepted/In Press date: 21 April 2016
e-pub ahead of print date: 28 April 2016
Published date: June 2016
Keywords: hep-ph, gr-qc, hep-th

Identifiers

Local EPrints ID: 429690
URI: http://eprints.soton.ac.uk/id/eprint/429690
ISSN: 0550-3213
PURE UUID: ceba7746-57dc-4690-a165-2fa832620018
ORCID for Daniel Burns: orcid.org/0000-0001-6976-1068

Catalogue record

Date deposited: 03 Apr 2019 16:30

Contributors

Author: Daniel Burns
Author: Sotirios Karamitsos
Author: Apostolos Pilaftsis