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Related papers: Squared Quartic Hilltop Inflation

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We investigate in detail a family of quintessential inflation models in the context of $R+R^2$ Palatini modified gravity. We find that successful inflation and quintessence are obtained with an inflaton scalar potential that is…

General Relativity and Quantum Cosmology · Physics 2021-02-26 Konstantinos Dimopoulos , Samuel Sánchez López

We consider $R^p$ inflation with $p \approx 2$, allowing small deviation from $R^2$ inflation. Using the inflaton potential in the Einstein frame, we construct a consistency relation between the scalar spectral index, the tensor-to-scalar…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-20 Hayato Motohashi

Scalar field models of inflation based on a large nonminimal coupling to gravity xi, in particular, Higgs inflation, may violate unitarity at an energy scale ~ M_p / xi << M_p. In this case the model is incomplete at energy scales relevant…

High Energy Physics - Phenomenology · Physics 2010-12-01 Rose N. Lerner , John McDonald

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

We briefly summarize the impact of the recent Planck measurements for string inflationary models, and outline what might be expected to be learned in the near future from the expected improvement in sensitivity to the primordial…

High Energy Physics - Theory · Physics 2015-06-16 C. P. Burgess , M. Cicoli , F. Quevedo

The early Universe inflation is well known as a promising theory to explain the origin of large scale structure of the Universe, a causal theory for the origin of primordial density fluctuations which may explain the observed density…

Astrophysics · Physics 2007-05-23 Xin-he Meng

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

A new setup of cosmic inflation with a periodic inflaton potential and conformal factor is discussed in the metric and Palatini formulations of gravity. As a concrete example, we focus on a natural-inflation-like inflaton potential, and…

General Relativity and Quantum Cosmology · Physics 2019-03-21 Ryusuke Jinno , Kunio Kaneta , Kin-ya Oda , Seong Chan Park

We study the low-temperature limit of warm inflation in a hilltop model. This limit remains valid up to the end of inflation, allowing an analytic description of the entire inflationary stage. In the weak dissipative regime, if the kinetic…

High Energy Physics - Phenomenology · Physics 2008-11-26 Juan Carlos Bueno Sanchez , Mar Bastero-Gil , Arjun Berera , Konstantinos Dimopoulos

We study inflationary models with a Gauss-Bonnet term to reconstruct the scalar field potentials and the Gauss-Bonnet coupling functions from the observable quantities. Using the observationally favored relations for both $n_s$ and $r$, we…

General Relativity and Quantum Cosmology · Physics 2017-06-14 Seoktae Koh , Bum-Hoon Lee , Gansukh Tumurtushaa

We investigate the feasibility of models of inflation with a large Gauss-Bonnet coupling at late times, which have been shown to modify and prevent the end of inflation. Despite the potential of Gauss-Bonnet models in predicting favourable…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-13 Carsten van de Bruck , Konstantinos Dimopoulos , Chris Longden

We consider $R^2$ inflation in the Palatini gravity assuming the existence of scalar fields, coupled to gravity in the most general manner. These theories, in the Einstein frame, and for one scalar field $h$, share common features with $K$…

General Relativity and Quantum Cosmology · Physics 2020-04-08 Ioannis D. Gialamas , A. B. Lahanas

We revisit the constraints that Planck 2015 temperature, polarization and lensing data impose on the parameters of warm inflation. To this end, we study warm inflation driven by a single scalar field with a quartic self interaction…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-26 Richa Arya , Arnab Dasgupta , Gaurav Goswami , Jayanti Prasad , Raghavan Rangarajan

We study the two-phase scenario following inflation, where the initial step is preheating, accompanied by a step of perturbative reheating at which inflaton field decays transferring all of its energy to create relativistic particles, the…

General Relativity and Quantum Cosmology · Physics 2021-05-03 Khalil El Bourakadi

We explore two saddle point inflationary scenarios in the context of higher order corrections related to different generalisations of general relativity. Firstly, we deal with Jordan frame Starobinsky potential, for which we identify a…

High Energy Physics - Theory · Physics 2016-02-17 Michal Artymowski , Zygmunt Lalak , Marek Lewicki

Recent observations from the Atacama Cosmology Telescope (ACT) indicate a moderate upward shift in the scalar spectral index $n_s$ compared to Planck $2018$, thereby placing tighter constraints on inflationary scenarios. Motivated by these…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-25 Li-Yang Chen , Rongrong Zha , Feng-Yi Zhang

In this article we confront both large-field and small-field sectors of mutated hilltop inflation model with the recent observational results. We begin with confrontation of predictions from mutated hilltop inflation with the joint analysis…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-17 Barun Kumar Pal

We study chaotic and runaway potential inflationary models in the curvaton scenario. In particular, we address the issue of large tensor-to-scalar ratio and red-tilted spectrum in chaotic models and reheating in runaway model in the light…

General Relativity and Quantum Cosmology · Physics 2020-08-27 Mohit Kumar Sharma , Kairat Myrzakulov , Mudhahir Al Ajmi

We study inflation driven by a slow-rolling inflaton field, characterised by a quadratic potential, and incorporating radiative corrections within the context of supergravity. In this model the energy scale of inflation is not overly…

High Energy Physics - Phenomenology · Physics 2011-02-16 Gabriel German , Graham Ross , Subir Sarkar

In this work, we study warm inflationary scenario based on a deformation of $R^{2}$ gravity. We start considering $R^{p}$ and assume $p=2(1+\delta)$ with $\delta\ll 1$ so that we simply obtain warm $R^{2}$ inflation when setting $\delta=0$.…

General Relativity and Quantum Cosmology · Physics 2022-12-20 Apirak Payaka , Waluka Amaek , Phongpichit Channuie