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The SUSY hybrid inflation model is found to dissipate radiation during the inflationary period. Analysis is made of parameter regimes in which these dissipative effects are significant. The scalar spectral index, its running, and the…

High Energy Physics - Phenomenology · Physics 2009-11-10 Mar Bastero-Gil , Arjun Berera

In the context of the Palatini formalism of gravity with an $R^{2}$ term, a $\phi^{2}$ potential can be consistent with the observed bound on $r$ whilst retaining the successful prediction for $n_{s}$. Here we show that the Palatini…

High Energy Physics - Phenomenology · Physics 2020-07-01 Amy Lloyd-Stubbs , John McDonald

Conditions are obtained for the existence of a warm inflationary attractor in the system of equations describing an inflaton coupled to radiation. These conditions restrict the temperature dependence of the dissipative terms and the size of…

Astrophysics · Physics 2011-07-13 Ian G Moss , Chun Xiong

We investigate how inflationary predictions are affected by the difference in the number of $e$-folds between the Jordan and Einstein frames. We study several test models in relation to a Jordan frame defined by the common…

General Relativity and Quantum Cosmology · Physics 2022-06-02 Antonio Racioppi , Martin Vasar

We study cosmological inflation and reheating in the unimodular f(R,T) gravity. During the reheating era, which takes place just after the end of inflation, the energy density of inflaton is converted to radiation energy through, for…

General Relativity and Quantum Cosmology · Physics 2022-11-23 Fateme Rajabi , Kourosh Nozari

A new model of thermal inflation is introduced, in which the mass of the thermal waterfall field is dependent on a light spectator scalar field. Using the $\delta N$ formalism, the "end of inflation" scenario is investigated in order to…

High Energy Physics - Phenomenology · Physics 2017-05-24 Konstantinos Dimopoulos , David H. Lyth , Arron Rumsey

We revisit the inflationary dynamics in detail for theories with Gauss-Bonnet gravity coupled to scalar functions, in light of the Planck data. Considering the chaotic inflationary scenario, we constrain the parameters of two models…

General Relativity and Quantum Cosmology · Physics 2017-02-08 Srijit Bhattacharjee , Debaprasad Maity , Rupak Mukherjee

We investigate the inflationary consequences of the oscillating dark energy model proposed by Ti\'an [\href{https://doi.org/10.1103/PhysRevD.101.063531}{Phys. Rev. D {\bf 101}, 063531 (2020)}], which aims to solve the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-29 S. X. Tian , Zong-Hong Zhu

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 reconsider the predictions of inflation for the spectral index of scalar (energy density) fluctuations (n_s) and the tensor/scalar ratio (r) using a discrete, model-independent measure of the degree of fine-tuning required to obtain a…

Astrophysics · Physics 2009-09-15 Latham A. Boyle , Paul J. Steinhardt , Neil Turok

In the present paper, we perform a sub-Planckian quantum mode analysis of linear cosmological perturbation in the inflaton field over a classical quasi de-Siter metric background by dynamical horizon exit (DHE) method. In this way, we probe…

General Relativity and Quantum Cosmology · Physics 2023-05-05 Arunoday Sarkar , Buddhadeb Ghosh

In this paper we study the reheating constraints on inflationary models considering perturbatively decaying inflaton. Important difference with the existing analysis is the inclusion of explicit decaying dynamics of inflaton during…

High Energy Physics - Theory · Physics 2020-11-05 Debaprasad Maity

In conventional model independent approaches, the power spectrum of primordial perturbations is characterized by such free parameters as spectral index, its running, the running of running, and the tensor-to-scalar ratio. In this work we,…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 Moslem Zarei

We study the two-field warm inflation models with a double quadratic potential and a linear temperature dependent dissipative coefficient. We derived the evolution equation of all kinds of perturbations without assuming slow-roll…

General Relativity and Quantum Cosmology · Physics 2019-05-23 Yang-yang Wang , Xiao-Min Zhang , Jian-Yang Zhu

Based on the dynamics of single scalar field slow-roll inflation and the theory of reheating, we investigate the generalized natural inflationary (GNI) model. Concretely, we give constraints on the scalar spectral index $n_{s}$ and…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-02 Nan Zhang , Ya-Bo Wu , Jun-Wang Lu , Chu-Wen Sun , Li-Jie Shou , Hai-Zhou Xu

In this paper we investigate the inflationary dynamics of an $f(R)$ gravity in the presence of a canonical scalar field. We specifically choose the cosmological evolution to be a quasi-de Sitter evolution and also the $f(R)$ gravity is…

General Relativity and Quantum Cosmology · Physics 2018-08-01 K. Kleidis , V. K. Oikonomou

The curvaton reheating in a non-oscillatory inflationary universe model is studied in a Jordan-Brans-Dicke theory. For different scenarios, the temperature of reheating is computed. The result tells us that the reheating temperature becomes…

Astrophysics · Physics 2009-11-11 Cuauhtemoc Campuzano , Sergio del Campo , Ramon Herrera

A scalar potential obtained from the $D$-term in the Supergravity models, which dominates over $F$ term and is mainly responsible for the inflationary phase in the early universe, is studied. The potential with canonical kinetic terms for…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-18 Rathin Adhikari , Mayukh R. Gangopadhyay , Yogesh

In this paper, we study the case of single field inflation within the framework of modified gravity theory where the gravity part has an arbitrary form $f(R)$. Via a conformal transformation, this case can be transformed into its Einstein…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-14 Taotao Qiu , Jun-Qing Xia

In this work we address the reheating issue in the context of $F(R)$ gravity, for theories that the inflationary era does not obey the slow-roll condition but the constant-roll condition is assumed. As it is known, the reheating era takes…

General Relativity and Quantum Cosmology · Physics 2017-10-10 V. K. Oikonomou