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Related papers: $\alpha$-Attractor and Reheating in a Model with N…

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We study $\alpha$-attractor models with both E-model and T-model potential in an extended Non-Minimal Derivative (NMD) inflation where a canonical scalar field and its derivatives are non-minimally coupled to gravity. We calculate the…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-19 Raheleh Shojaee , Kourosh Nozari , Farhad Darabi

We eliminate the parameters originally present in models of inflation of the $\alpha$-attractor type in favor of the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$. We then write expressions for the number of $e$-folds…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-02 Gabriel German

We consider the inflaton as a scalar field described by a non-minimal derivative coupling model with a power law potential. We study the slow roll inflation, the rapid oscillation phase, the radiation dominated and the recombination eras…

General Relativity and Quantum Cosmology · Physics 2015-06-12 H. Mohseni Sadjadi , Parviz Goodarzi

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

Motivated by $\alpha$-attractor models, in this paper we consider a Gauss-Bonnet inflation with E-model type of potential. We consider the Gauss-Bonnet coupling function to be the same as the E-model potential. In the small $\alpha$ limit…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-02 Kourosh Nozari , Narges Rashidi

We present an explicit cosmological model where inflation and dark energy both could arise from the dynamics of the same scalar field. We present our discussion in the framework where the inflaton field $\phi$ attains a nearly constant…

High Energy Physics - Theory · Physics 2008-11-26 Ishwaree P. Neupane

In this paper, we discuss the constraints on the reheating temperature supposing an early post-reheating cosmological phase dominated by one or more simple scalar fields produced from inflaton decay and decoupled from matter and radiation.…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-26 Alessandro Di Marco , Gianfranco Pradisi , Paolo Cabella

We present a systematic method for evaluation of perturbation observables in non-canonical single-field inflation models within the slow-roll approximation, which allied with field redefinitions enables predictions to be established for a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Sheng Li , Andrew R Liddle

This paper revisits the Inflationary scenario within the framework of scalar field models possessing a non-canonical kinetic term. We obtain closed form solutions for all essential quantities associated with chaotic inflation including slow…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-03 Sanil Unnikrishnan , Varun Sahni , Aleksey Toporensky

In a series of recent papers Kallosh, Linde, and collaborators have provided a unified description of single-field inflation with several types of potentials, ranging from power law to supergravity, in terms of just one parameter $\alpha$.…

High Energy Physics - Theory · Physics 2016-02-03 Massimiliano Rinaldi , Luciano Vanzo , Sergio Zerbini , Giovanni Venturi

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

Picking out DBI scalar field as inflation, the slow-rolling inflationary scenario is studied by attributing an exponential time function to scale factor; known as intermediate inflation. The perturbation parameters of the model are…

General Relativity and Quantum Cosmology · Physics 2017-08-15 N. Nazavari , A. Mohammadi , Z. Ossoulian , Kh. Saaidi

We study observational viability of Natural Inflation with a tachyon field as inflaton. By obtaining the main perturbation parameters in this model, we perform a numerical analysis on the parameter space of the model and in confrontation…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Narges Rashidi , Kourosh Nozari , Oyvind Gron

We derive a lower bound on the field excursion for the tachyon inflation, which is determined by the amplitude of the scalar perturbation and the number of $e$-folds before the end of inflation. Using the relation between the observables…

General Relativity and Quantum Cosmology · Physics 2017-08-17 Qin Fei , Yungui Gong , Jiong Lin , Zhu Yi

We study the reheating phase following inflation in the context of single-field models, focusing on the perturbative decay of the inflaton into lighter particles. A general analytical framework is presented to compute the reheating…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-18 Gabriel German

A plethora of inflationary models can produce interesting small-scale phenomenology, such as enhanced scalar fluctuations leading to primordial black hole (PBH) production and large scalar-induced GW. Nevertheless, good models must…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-10 Laura Iacconi , Michael Bacchi , Luiz Filipe Guimarães , Felipe T. Falciano

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

We study DBI inflation based upon a general model characterized by a power-law flow parameter $\epsilon(\phi)\propto\phi^{\alpha}$ and speed of sound $c_s(\phi)\propto\phi^{\beta}$, where $\alpha$ and $\beta$ are constants. We show that in…

General Relativity and Quantum Cosmology · Physics 2009-10-02 Dennis Bessada , William H. Kinney , Konstantinos Tzirakis

Cosmological $\alpha$-attractors stand out as particularly compelling models to describe inflation in the very early universe, naturally meeting tight observational bounds from cosmic microwave background (CMB) experiments. We investigate…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 Laura Iacconi , Hooshyar Assadullahi , Matteo Fasiello , David Wands

Bayesian inference techniques are used to investigate situations where an additional light scalar field is present during inflation and reheating. This includes (but is not limited to) curvaton-type models. We design a numerical pipeline…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-13 Vincent Vennin , Kazuya Koyama , David Wands
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