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Related papers: Reconstructing inflation in scalar-torsion $f(T,\p…

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A modified gravity theory with $f(R)=R^2$ coupled to a dark energy lagrangian $L=-V(\phi)F(X)$ , $X=\nabla_{\mu}\phi\nabla^{\mu}\phi$, gives plausible cosmological scenarios when the modified Friedman equations are solved subject to the…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-30 Debashis Gangopadhyay , Somnath Mukherjee

We show that embedding Natural Inflation in a more general scalar-tensor theory, with non-minimal couplings to the Ricci scalar and the kinetic term, alleviates the current tension of Natural Inflation with observational data. The coupling…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-15 Guillem Simeon

We show how short inflation naturally arises in a non-minimal gravity theory with a scalar field without any potential terms. This field drives inflation solely by its derivatives, which couple to the matter only through the combination…

High Energy Physics - Phenomenology · Physics 2010-04-05 Nemanja Kaloper

We perform a Bayesian study of a generalization of the basic $\alpha$-attractor T model given by the potential $V(\phi)=V_0\left[1-\text{sech}^{p}\left(\phi/\sqrt{6\alpha}M_{pl}\right)\right]$ where $\phi$ is the inflaton field and the…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 Francisco X. Linares Cedeño , Gabriel German , Juan Carlos Hidalgo , Ariadna Montiel

We study a single fluid component in a flat like universe (FLU) governed by $f(T)$ gravity theories, where $T$ is the teleparallel torsion scalar. The FLU model, regardless the value of the spatial curvature $k$, identifies a special class…

High Energy Physics - Theory · Physics 2016-10-19 W. El Hanafy , G. G. L. Nashed

Solid inflation is a cosmological model where inflation is driven by fields which enter the Lagrangian in the same way as body coordinates of a solid matter enter the equation of state, spontaneously breaking spatial translational and…

General Relativity and Quantum Cosmology · Physics 2019-03-18 Peter Mészáros

We perform an analysis of models of chaotic inflation where the inflaton field $\phi$ is coupled non-minimally to gravity via $\xi \phi^n g^{\mu\nu}R_{\mu\nu}(\Gamma), n>0$. We focus on the Palatini theory of gravity, i.e. the case where…

General Relativity and Quantum Cosmology · Physics 2018-04-20 Laur Järv , Antonio Racioppi , Tommi Tenkanen

Inflationary slow-roll dynamics in Einstein gravity with a non-minimal scalar-curvature coupling can be equivalent to that in the certain f(R) gravity theory. We review the correspondence and extend it to N=1 supergravity. The non-minimal…

High Energy Physics - Theory · Physics 2015-06-04 Sergei V. Ketov , Alexei A. Starobinsky

A technique for the reconstruction of the potential for a scalar field in cosmological models based on induced gravity has recently been developed by Alexander Y. Kamenshchik, Alessandro Tronconi, and Giovanni Venturi \cite{ref1}. In this…

General Relativity and Quantum Cosmology · Physics 2018-12-27 Behzad Tajahmad

We propose an extension of the Higgs inflation to the hybrid metric-Palatini gravity, where we introduce non-minimal couplings between Higgs and both the metric-type and the Palatini-type Ricci scalars. We study the inflationary…

High Energy Physics - Theory · Physics 2023-05-30 Minxi He , Yusuke Mikura , Yuichiro Tada

We consider slow-roll inflation in the context of a modified Brans-Dicke dilaton gravity. From a two self-interacting potentials $V(\phi)$, we reproduce a Starobinsky-like potential and, commonly in syperstring models, an exponential tail…

General Relativity and Quantum Cosmology · Physics 2024-11-11 Abraão J. S. Capistrano , Gilberto M. Kremer

In this work, we explored warm inflation in the background of $f(R,T)$ gravity in the strong dissipation regime. Considering scalar field for FLRW universe, we derived modified field equations. We then deduced slow-roll parameters under…

General Relativity and Quantum Cosmology · Physics 2023-11-07 Biswajit Deb , Sabina Yeasmin , Atri Deshamukhya

If primordial scalar and tensor perturbation spectra can be inferred from observations of the cosmic background radiation and large-scale structure, then one might hope to reconstruct a unique single-field inflaton potential capable of…

Astrophysics · Physics 2016-08-25 Edmund J. Copeland , Ian J. Grivell , Edward W. Kolb , Andrew R. Liddle

We reconsider non-minimal \lambda \phi^4 chaotic inflation which includes the gravitational coupling term \xi \mathcal{R} \phi^2, where \phi denotes a gauge singlet inflaton field and \mathcal{R} is the Ricci scalar. For \xi >> 1 we…

High Energy Physics - Phenomenology · Physics 2014-11-21 Nobuchika Okada , Mansoor Ur Rehman , Qaisar Shafi

We investigate the cosmological reconstruction in modified f(R,T) gravity, where R is the Ricci scalar and T the trace of the stress-energy tensor. Special attention is attached to the case in which the function f is given by f (R, T) = f1…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 M. J. S. Houndjo

We consider a scenario in which the inflaton $\phi$ is a pseudoscalar field non-minimally coupled to gravity through a term of the form ${\cal X} R \phi^2$. The pseudoscalar is also coupled to a $U(1)$ gauge field (or an ensemble of ${\cal…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-17 Juan P. Beltrán Almeida , Nicolás Bernal

In this paper we analyze scalar gravitational perturbations on a Robertson-Walker background in the presence of multiple scalar fields that take values on a (geometrically non-trivial) field manifold during slow-roll inflation. For this…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Groot Nibbelink , B. J. W. van Tent

We study the inflationary scenario in the Tsallis entropy-based cosmology. The Friedmann equations in this setup can be derived by using the first law of thermodynamics. To derive the relations of the power spectra of the scalar and tensor…

General Relativity and Quantum Cosmology · Physics 2024-01-26 Zeinab Teimoori , Kazem Rezazadeh , Abasat Rostami

Using the constant-roll approach, DBI inflationary scenario will be studied and it is sought to compare the result with observational data. By considering the cosmological perturbations of the model, it is realized that some extra terms…

General Relativity and Quantum Cosmology · Physics 2020-05-12 Abolhassan Mohammadi , Tayeb Golanbari , Khaled Saaidi

Here, a natural non-canonical inflationary model based on a power-law Lagrangian is investigated. We analyze the scalar spectral index $n_{\rm s}$ and the tensor-to-scalar ratio $r$ of the model and identify their degeneracies with respect…

General Relativity and Quantum Cosmology · Physics 2026-02-05 Karam Bahari , Soma Heydari , Kayoomars Karami
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