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Related papers: Non-minimally Coupled Scalar $k$-Inflation Dynamic…

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We propose the generic no-scale inflation inspired from string theory compactifications. We consider the K\"ahler potentials with an inflaton field $\varphi$, as well as one, two, and three K\"ahler moduli. Also, we consider the…

High Energy Physics - Phenomenology · Physics 2022-08-09 Lina Wu , Tianjun Li

For a robust interpretation of upcoming observations from PLANCK and LHC experiments it is imperative to understand how the inflationary dynamics of a non-minimally coupled Higgs scalar field with gravity may affect the determination of the…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 L. A. Popa , A. Caramete

In this paper, we analyze the early-time inflation in a scalar-tensor theory of gravity where the scalar field is minimally coupled with the Gauss-Bonnet four dimensional topological invariant. The theory belongs to a class of Horndeski…

General Relativity and Quantum Cosmology · Physics 2017-12-11 Lorenzo Sebastiani , Shynaray Myrzakul , Ratbay Myrzakulov

We investigate inflation within $f(R,\phi)$-theories, where a dynamical scalar field is coupled to gravity. A class of models which can support early-time acceleration with the emerging of an effective cosmological constant at high…

General Relativity and Quantum Cosmology · Physics 2018-12-13 R. Myrzakulov , L. Sebastiani , S. Vagnozzi

We investigate a class of inflationary models in modified gravity theories which contain a non-minimal coupling between gravity and a scalar field $\phi$ (inflaton) as $f(R,T)=R \bigl(1+\alpha+ \kappa^4 \beta T \bigr)+\kappa^2\gamma T $…

General Relativity and Quantum Cosmology · Physics 2024-12-03 Payel Sarkar , Ashmita , Prasanta Kumar Das

We investigate inflationary dynamics in the framework of the Einstein-Gauss-Bonnet gravity. In the model under consideration, the inflaton field is non-minimally coupled to the Gauss-Bonnet curvature invariant, so that the latter appears to…

General Relativity and Quantum Cosmology · Physics 2020-09-02 Ekaterina O. Pozdeeva , Mayukh Raj Gangopadhyay , Mohammad Sami , Alexey V. Toporensky , Sergey Yu. Vernov

We propose new slow-roll approximations for inflationary models with the Gauss-Bonnet term. We find more accurate expressions of the standard slow-roll parameters as functions of the scalar field. To check the accuracy of approximations…

General Relativity and Quantum Cosmology · Physics 2024-09-24 Ekaterina O. Pozdeeva , Maria A. Skugoreva , Alexey V. Toporensky , Sergey Yu. Vernov

In this paper we will illustrate how to constrain unavoidable K\"ahler corrections for ${\cal N}=1$ supergravity (SUGRA) inflation from the recent Planck data. We will show that the non-renormalizable K\"ahler operators will induce in…

High Energy Physics - Theory · Physics 2014-04-15 Sayantan Choudhury , Anupam Mazumdar , Ernestas Pukartas

In this short note we discuss the possibility of producing a slow rolling inflationary background by considering a massive scalar field whose kinetic term is non-minimally coupled to gravity.

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Cristiano Germani , Alex Kehagias

We show that an inflationary background might be realized by using any p-form non-minimally coupled to gravity. Standard scalar field inflation corresponds to the 0-form case and vector inflation to the 1-form. Moreover, we show that the 2-…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 Cristiano Germani , Alex Kehagias

Cosmological inflation remains a key paradigm for explaining the earliest stages of the Universe, yet the theoretical limitations of General Relativity (GR) motivate the development of alternative formulations capable of addressing both…

General Relativity and Quantum Cosmology · Physics 2025-11-13 Maryam Shiravand , Saeed Fakhry , Javad T. Firouzjaee , Ali Tizfahm

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 -…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-26 Pedro G. Ferreira , Christopher T. Hill , Johannes Noller , Graham G. Ross

The equivalence between $f(R)$ and scalar-tensor theories is revisited, we consequently explored different $f(R)$ models. After consideration of specific definition of the scalar field, we derived the potentials $V(\phi)$ for each $f(R)$…

General Relativity and Quantum Cosmology · Physics 2022-09-20 Beatrice Murorunkwere , Fidele Twagirayezu , Albert Munyeshyaka , Joseph Ntahompagaze , Abraham Ayirwanda

We extend the theory of cosmological perturbations to the case when the ``matter'' Lagrangian is an arbitrary function of the scalar field and its first derivatives. In particular, this extension provides a unified description of known…

High Energy Physics - Theory · Physics 2009-07-09 Jaume Garriga , V. F. Mukhanov

The oscillating inflation model recently proposed by Damour and Mukhanov is investigated with a non-minimal coupling. Numerical study confirms an inflationary behavior and the density perturbation is obtained. A successful inflation…

High Energy Physics - Theory · Physics 2019-08-17 Jae-weon Lee , Seoktae Koh , Chanyong Park , Sang Jin Sin , Chul H. Lee

There is increasing evidence from string theory that effective field theories are only reliable over approximately sub-Planckian field excursions. The two most promising effective models for early universe cosmology, inflation and…

High Energy Physics - Theory · Physics 2018-11-14 Jean-Luc Lehners

We propose a scenario of the beginning of inflation in which the non-vacuum value of the scalar field that drives inflation develops dynamically due to the non-minimal coupling to gravity. In this scenario, inflation emerges as an…

High Energy Physics - Phenomenology · Physics 2016-09-06 M. V. Libanov , V. A. Rubakov , P. G. Tinyakov

In inflation with nonminimal derivative coupling there is not a conformal transformation to the Einstein frame where calculations are straightforward, and thus in order to extract inflationary observables one needs to perform a detailed and…

General Relativity and Quantum Cosmology · Physics 2016-10-14 Haidar Sheikhahmadi , Emmanuel N. Saridakis , Ali Aghamohammadi , Khaled Saaidi

Inflationary models are usually based on dynamics of one or more scalar fields coupled to gravity. In this work we present a new class of inflationary models, gauge-flation or non-Abelian gauge field inflation, where slow-roll inflation is…

High Energy Physics - Phenomenology · Physics 2015-03-18 A. Maleknejad , M. M. Sheikh-Jabbari

We explain why the concept of a spontaneously broken superconformal symmetry is useful to describe inflationary models favored by the Planck. Non-minimal coupling of complex scalars to curvature, N(X, X*) R, is compulsory for superconformal…

High Energy Physics - Theory · Physics 2014-02-05 Renata Kallosh
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