Bombacigno, F. orcid.org/0000-0003-2869-0907, De Angelis, M. orcid.org/0000-0003-3432-8250, van de Bruck, C. orcid.org/0000-0001-8311-8941 et al. (1 more author) (2025) Inflation in non-local hybrid metric-Palatini gravity. Journal of Cosmology and Astroparticle Physics, 2025 (05). 025. ISSN 1475-7516
Abstract
Within the framework of hybrid metric-Palatini gravity, we incorporate non-localities introduced via the inverse of the d'Alembert operators acting on the scalar curvature. We analyze the dynamical structure of the theory and, adopting a scalar-tensor perspective, assess the stability conditions to ensure the absence of ghost instabilities. Focusing on a special class of well-defined hybrid actions — where local and non-local contributions are carried by distinct types of curvature — we investigate the feasibility of inflation within the resulting Einstein-frame multi-field scenario. We examine how the non-minimal kinetic couplings between the fields, reflecting the non-local structure of the original frame, influence the number of e-folds and the field trajectories. To clarify the physical interpretation of our results, we draw analogies with benchmark single-field inflation scenarios that include spectator fields.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2025 The Author(s). Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. http://creativecommons.org/licenses/by/4.0/ |
Keywords: | Gauss-Bonnet-Lovelock-Horndeski-Palatini etc gravity theories; modified gravity; inflation |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematical and Physical Sciences |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 19 May 2025 11:21 |
Last Modified: | 19 May 2025 11:21 |
Status: | Published |
Publisher: | IOP Publishing |
Refereed: | Yes |
Identification Number: | 10.1088/1475-7516/2025/05/025 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:226811 |
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Filename: Bombacigno_2025_J._Cosmol._Astropart._Phys._2025_025.pdf
Licence: CC-BY 4.0