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Related papers: Kinetically Modified Palatini Inflation Meets ACT …

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In the context of Palatini gravity, $F(R+X)$ models, with X the inflaton kinetic term, are characterized by the appealing property of generating asymptotically flat inflaton potentials, exactly like the more commonly studied Palatini $F(R)$…

General Relativity and Quantum Cosmology · Physics 2025-12-22 N. Bostan , R. H. Dejrah , C. Dioguardi , A. Racioppi

If the inflaton and the quintessence fields are identified, the background geometry evolves through a stiff epoch undershooting the expansion rate of a radiation-dominated plasma. For some classes of inflationary potentials this scenario is…

General Relativity and Quantum Cosmology · Physics 2020-01-08 Massimo Giovannini

For the models of inflation driven by the potential energy of an inflaton field $\phi$, the covariant Galileon Lagrangian $(\partial\phi)^2\Box \phi$ generally works to slow down the evolution of the field. On the other hand, if the…

General Relativity and Quantum Cosmology · Physics 2013-01-29 Junko Ohashi , Shinji Tsujikawa

The advent of high-precision cosmological observations has challenged many traditional inflationary models. Data from $Planck$ 2018 along with the BICEP/$Keck$ 2018 result have already ruled out most of the established models by placing…

General Relativity and Quantum Cosmology · Physics 2026-05-27 Biswajit Deb , Atri Deshamukhya

In this work, we revisit the Witten-O'Raifeartaigh model of inflation, in which the potential takes a $\operatorname{log}^2(\phi/M)$ form, when the scalar field is non-minimally coupled to gravity. We investigate the impact of the coupling…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-10 F. B. M. dos Santos , R. Silva

We study chaotic inflation driven by a real, massive, homogeneous minimally coupled scalar field in a flat Robertson-Walker spacetime. The semiclassical limit for gravity is considered, whereas the scalar field is treated quantum…

General Relativity and Quantum Cosmology · Physics 2008-11-26 F. Finelli , G. P. Vacca , G. Venturi

By applying a particular kind of modified gravity, we study the inflation. Precisely, we extend our investigations beyond the Einstein's gravity to explore the Natural inflation model via the term $F(\phi)T$. We compute the inflation…

General Relativity and Quantum Cosmology · Physics 2025-07-30 Feyzollah Younesizadeh , Davoud Kamani

Models of inflation in which the Higgs field is non-minimally coupled to gravity lead, after a recaling of the metric, to a complicated expression for the potential of the inflaton field. Nevertheless, this potential produces the desired…

High Energy Physics - Theory · Physics 2022-06-08 Noureddine Mohammedi

We revisit the no-scale ripple inflation model, where no-scale supergravity is modified by an additional term for the inflaton field in the Kahler potential. This term not only breaks one SU(N,1) symmetry explicitly, but also plays an…

High Energy Physics - Phenomenology · Physics 2015-06-17 Tianjun Li , Zhijin Li , Dimitri V. Nanopoulos

A new shifted hybrid inflationary scenario is introduced which, in contrast to the older one, relies only on renormalizable superpotential terms. This scenario is automatically realized in a concrete extension of the "minimal"…

High Energy Physics - Phenomenology · Physics 2009-11-07 R. Jeannerot , S. Khalil , G. Lazarides

We review the status of the Starobinsky-like models for inflation beyond minimal gravity and discuss the unitarity problem due to the presence of a large non-minimal gravity coupling. We show that the induced gravity models allow for a…

High Energy Physics - Phenomenology · Physics 2018-01-24 Hyun Min Lee

We consider here natural inflation in the low energy (two-derivative) metric-affine theory containing only the minimal degrees of freedom in the inflationary sector, i.e. the massless graviton and the pseudo-Nambu-Goldstone boson (PNGB).…

High Energy Physics - Phenomenology · Physics 2024-10-07 Antonio Racioppi , Alberto Salvio

In this work we shall study $k$-inflation theories with non-minimal coupling of the scalar field to gravity, in the presence of only a higher order kinetic term of the form $\sim \mathrm{const}\times X^{\mu}$, with…

General Relativity and Quantum Cosmology · Physics 2021-01-05 V. K. Oikonomou

In this work, we investigated several inflationary scenarios within the framework of modified $f(Q,\phi)$ gravity with a nonminimal coupling between the scalar field and the nonmetricity scalar. We focused on the impact of the coupling…

General Relativity and Quantum Cosmology · Physics 2026-04-30 F. Mavoa , M. B. Barry , R. Ndioukane , M. G. Ganiou , F. K. Ahloui

This study examines how inflationary dynamics are affected by $f(R)$ theories with a non-minimal coupling between matter and curvature. Both positive and negative corrections to the minimal coupling of General Relativity are considered, and…

General Relativity and Quantum Cosmology · Physics 2026-01-29 Miguel Barroso Varela , Orfeu Bertolami , Andreas Mantziris

We study inflation driven by a slow-rolling inflaton field, characterised by a quadratic potential, and incorporating radiative corrections within the context of supergravity. In this model the energy scale of inflation is not overly…

High Energy Physics - Phenomenology · Physics 2011-02-16 Gabriel German , Graham Ross , Subir Sarkar

We consider a modified gravity framework for inflation by adding to the Einstein-Hilbert action a direct $f(\phi)T$ term, where $\phi$ is identified as the inflaton and $T$ is the trace of the energy-momentum tensor. The framework goes to…

General Relativity and Quantum Cosmology · Physics 2022-02-23 Xinyi Zhang , Che-Yu Chen , Yakefu Reyimuaji

Over the last four decades, a number of modified gravity theories have been proposed to study cosmological phenomena as they can provide solutions for some of the shortcomings of Einstein's gravity in explaining early and late time…

General Relativity and Quantum Cosmology · Physics 2026-01-05 Biswajit Deb , Atri Deshamukhya

An N=1 Poincare supergravity action, suitable for describing the Starobinsky inflation, is proposed. It extends f(R) gravity to supergravity in its old-minimal version. The action is parametrized by a single holomorphic potential and a…

High Energy Physics - Theory · Physics 2013-12-30 Sergei V. Ketov

A new modified string-inspired modular invariant supergravity model is proposed and is applied to realize the slow roll inflation in Einstein frame. Because inflation deals with Planck scale physics, the dilaton can be a strong candidate…

High Energy Physics - Phenomenology · Physics 2011-04-22 Mitsuo J. Hayashi , Yuta Koshimizu , Toyokazu Fukuoka , Kenji Takagi , Hikoya Kasari