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A new inflationary scenario driven by a slowly-rolling homogeneous scalar field whose potential $V\left(\varphi\right)$ is given by a generalized exponential function is investigated. Within the {\it slow-roll} approximation we obtain the…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-17 B. W. Ribeiro , I. M. Macêdo , F. C. Carvalho

We study quintessential inflation using a generalized exponential potential $V(\phi)\propto exp(-\lambda \phi^n/Mpl^n), n>1$, the model admits slow-roll inflation at early times and leads to close-to-scaling behaviour in the post…

General Relativity and Quantum Cosmology · Physics 2017-06-21 Chao-Qiang Geng , Chung-Chi Lee , M. Sami , Emmanuel N. Saridakis , Alexei A. Starobinsky

We investigate a constraint on reheating followed by alpha-attractor-type inflation (the E-model and T-model) from an observation of the spectral index n_s. When the energy density of the universe is dominated by an energy component with…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-04 Yoshiki Ueno , Kazuhiro Yamamoto

We derive the reconstruction formulae for the inflation model with the non-minimal derivative coupling term. If reconstructing the potential from the tensor-to-scalar ratio, we could obtain the potential without using the high friction…

General Relativity and Quantum Cosmology · Physics 2020-11-23 Qin Fei , Zhu Yi , Yingjie Yang

In this paper, we apply reconstruction techniques to recover the potential parameters for a particular class of single-field models, the $\alpha$-attractor (supergravity) models of inflation. This also allows to derive the inflaton vacuum…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-28 A. Di Marco , P. Cabella , N. Vittorio

A safe way to reheat the universe, in models of natural and quadratic inflation, is through shift symmetric couplings between the inflaton $\phi$ and the Standard Model (SM), since they do not generate loop corrections to the potential…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-04 Ricardo Z. Ferreira , Alessio Notari

In this work we shall study a new class of attractor models which we shall call generalized $R^p$-attractor models. This class of models is based on a generalization of the Einstein frame potential of $R^p$ $f(R)$ gravity models in the…

General Relativity and Quantum Cosmology · Physics 2023-02-08 S. D. Odintsov , V. K. Oikonomou

The simplest inflationary model $V=\frac12 m^2\phi^2$ represents the benchmark for future constraints. For a quadratic potential, the quantity $(n_s-1)+r/4+11 (n_s-1)^2/24$ vanishes (up to corrections which are cubic in slow roll) and can…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-15 Paolo Creminelli , Diana López Nacir , Marko Simonović , Gabriele Trevisan , Matias Zaldarriaga

We investigate the reconstruction of standard and generalized Rastall gravity inflationary models, using the scalar spectral index and the Rastall parameter expressed as functions of the number of $e-$folds $N$. Within a general formalism,…

General Relativity and Quantum Cosmology · Physics 2025-12-09 Ramon Herrera , Carlos Rios

The reconstruction of an inflationary universe in the context of the Galileon model or G-model, considering as attractors the scalar spectral index $n_S(N)$ and the tensor to scalar ratio $r(N)$ as a function of the number of e-folding $N$…

General Relativity and Quantum Cosmology · Physics 2018-08-08 Ramon Herrera

Inflationary $\alpha$-attractor models can be naturally implemented in supergravity with hyperbolic geometry. They have stable predictions for observables, such as $n_s=1-{2/ N_e} $, assuming that the potential in terms of the original…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-20 Renata Kallosh , Andrei Linde

I describe a simple class of $\alpha$-attractors, generalizing the single-field GL model of inflation in supergravity. The new class of models is defined for $0<\alpha \lesssim 1$, providing a good match to the present cosmological data. I…

High Energy Physics - Theory · Physics 2015-05-20 Andrei Linde

We propose a class of inflation models with potential V(\phi)=\alpha \phi^n exp(-\beta^m \phi^m). We show that such kind of inflaton potentials can be realized in supergravity theory with a small shift symmetry breaking term in the K\"ahler…

High Energy Physics - Phenomenology · Physics 2015-06-18 Tianjun Li , Zhijin Li , Dimitri V. Nanopoulos

We propose a modification on the super-potential of (arXiv: 1901.09046) which discusses the simplest construction of inflationary $\alpha$ attractor models (also called T/E models) in supergravity without the sinflaton. This can make all…

High Energy Physics - Phenomenology · Physics 2020-12-09 Ping Kwan Man Ellgan

We study the tensor spectral index $n_t$ and the tensor-to-scalar ratio $r$ in the simplest multifield extension to single-field, slow-roll inflation models. We show that multifield models with potentials $V \sim \sum_i \lambda_i…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Layne C. Price , Hiranya V. Peiris , Jonathan Frazer , Richard Easther

In this work we generalize the constant-roll condition for minimally coupled canonical scalar field inflation. Particularly, we shall assume that the scalar field satisfies the condition $\ddot{\phi}=\alpha (\phi) V'(\phi)$, and we derive…

General Relativity and Quantum Cosmology · Physics 2022-05-25 V. K. Oikonomou

We construct $\alpha$-attractor versions of hybrid inflation models. In these models, the potential of the inflaton field $\varphi$ is uplifted by the potential of the second field $\chi$. This uplifting ends due to a tachyonic instability…

High Energy Physics - Theory · Physics 2022-08-31 Renata Kallosh , Andrei Linde

We investigate the inflationary attractors in models of inflation inspired from general conformal transformation of general scalar-tensor theories to the Einstein frame. The coefficient of the conformal transformation in our study depends…

General Relativity and Quantum Cosmology · Physics 2019-07-31 Khamphee Karwan , Phongpichit Channuie

In negatively curved field spaces, inflation can be realised even in steep potentials. Hyperinflation invokes the `centrifugal force' of a field orbiting the hyperbolic plane to sustain inflation. We generalise hyperinflation by showing…

High Energy Physics - Theory · Physics 2019-05-22 Theodor Bjorkmo , M. C. David Marsh

After Planck 2013, a broad class of inflationary models called \alpha-attractors was developed which has universal observational predictions. For small values of the parameter \alpha, the models have good consistency with the recent CMB…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-22 Mehdi Eshaghi , Moslem Zarei , Nematollah Riazi , Ahmad Kiasatpour