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Related papers: Improving Slow-Roll Estimates in Starobinsky Infla…

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Inflation in cosmology is a specific stage preceding the Big Bang, aimed at solving both old background problems and new perturbation issues. Single-field inflation is a candidate to illustrate the picture of the initial universe, and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-21 Guanqiao Liu

The effective field theory (EFT) of inflation provides an essential picture to explore the effects of the unknown high energy physics in the single scalar field inflation models. For a generic EFT of inflation, possible high energy…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Guang-Hua Ding , Jin Qiao , Qiang Wu , Tao Zhu , Anzhong Wang

The primordial power spectra of scalar and tensor perturbations during slow-roll inflation are usually calculated with the method of Bessel function approximation. For constant-roll or ultra slow-roll inflation, the method of Bessel…

General Relativity and Quantum Cosmology · Physics 2018-04-09 Zhu Yi , Yungui Gong

We consider the simplest extension to the Starobinsky model, by allowing an extra scalar field to help drive inflation. We perform our analysis in the Einstein frame and calculate the power spectra at the end of inflation to second order in…

High Energy Physics - Theory · Physics 2015-10-21 Carsten van de Bruck , Laura Elena Paduraru

In our paper we consider the validity of slow-roll approximations for Gauss-Bonnet inflation introduced in [1]. In contrast to the cited paper where the coupling function before the Gauss-Bonnet term have been chosen as a decaying function…

General Relativity and Quantum Cosmology · Physics 2026-02-02 Bogdan A. Rudenko , Maria A. Skugoreva , Alexey V. Toporensky

Stochastic inflation describes the global structure of the inflationary universe by modeling the super-Hubble dynamics as a system of matter fields coupled to gravity where the sub-Hubble field fluctuations induce a stochastic force into…

High Energy Physics - Theory · Physics 2008-11-26 Andrew J. Tolley , Mark Wyman

The recent local measurement of the Hubble constant based on the distance-ladder method has reached a $1.91\%$ precision, but this result is in tension with the early-universe measurements at the more than 4$\sigma$ level, bringing a crisis…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-12 Rui-Yun Guo , Jing-Fei Zhang , Xin Zhang

We study inflation induced by (power-low) scalar curvature corrections to General Relativity. The class of inflationary scalar potentials $V(\sigma)\sim\exp[n\,\sigma]$, $n$ general parameter, is investigated in the Einsein frame and the…

General Relativity and Quantum Cosmology · Physics 2014-09-22 L. Sebastiani , G. Cognola , R. Myrzakulov , S. D. Odintsov , S. Zerbini

Holographic considerations may provide a glimpse of quantum gravity beyond what is currently accessible by other means. Here we apply holography to inflationary cosmology. We argue that the appropriate holographic bound on the total entropy…

High Energy Physics - Theory · Physics 2007-05-23 Andreas Albrecht , Nemanja Kaloper , Yong-Seon Song

In the context of effective theories of gravity, a minimalist bottom-up approach which takes into account $1$-loop quantum corrections leads to modifications in the Einstein-Hilbert action through the inclusion of four extra terms: $R^{2}$,…

General Relativity and Quantum Cosmology · Physics 2023-01-27 J. Bezerra-Sobrinho , L. G. Medeiros

We are on the verge of the first precision testing of the inflationary cosmology as a model for the origin of structure in the Universe. I review the key predictions of inflation which can be used as observational tests, in the sense of…

Astrophysics · Physics 2007-05-23 Andrew R Liddle

In this paper, we study the Starobinsky model of inflation in the context of gravity's rainbow theory. We propose that gravity rainbow functions can be written in the power-law form of the Hubble parameter. We present a detailed derivation…

General Relativity and Quantum Cosmology · Physics 2016-02-11 Auttakit Chatrabhuti , Vicharit Yingcharoenrat , Phongpichit Channuie

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 present a joint Bayesian analysis to impose constraints on the generalized $\alpha$-Starobinsky inflationary model using the high-precision cosmological datasets: Planck, CMB lensing from ACT DR6, and Baryon Acoustic Oscillations (BAO)…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-27 Karim Carrion , Francisco X. Linares Cedeño , Gabriel Germán , Juan Carlos Hidalgo

We propose a new four-parameter entropy function that generalizes the Tsallis, R\'{e}nyi, Barrow, Sharma-Mittal, Kaniadakis and Loop Quantum Gravity entropies for suitable limits of the parameters. Consequently, we address the early and…

General Relativity and Quantum Cosmology · Physics 2022-06-15 Shin'ichi Nojiri , Sergei D. Odintsov , Tanmoy Paul

We consider approaches to cosmological parameter estimation in the inflationary cosmology, focussing on the required accuracy of the initial power spectra. Parametrizing the spectra, for example by power-laws, is well suited to testing the…

Astrophysics · Physics 2009-11-07 Samuel M. Leach , Andrew R. Liddle , Jerome Martin , Dominik J. Schwarz

An inflationary scenario driven by a slow rolling homogeneous scalar field whose potential $V(\Phi)$ is given by a generalized exponential function is discussed. Within the {\sl slow-roll} approximation we investigate some of the main…

Astrophysics · Physics 2008-11-26 J. S. Alcaniz , F. C. Carvalho

This study concerns the consistency of the tachyon warm inflationary models. A linear stability analysis is performed to find the slow-roll conditions, characterized by the potential slow-roll (PSR) parameters, for the existence of a…

General Relativity and Quantum Cosmology · Physics 2014-02-25 Xiao-Min Zhang , Jian-Yang Zhu

$k$-inflation represents the most general single-field inflation, in which the perturbations usually obey an equation of motion with a time-dependent sound speed. In this paper, we study the observational predictions of the $k$-inflation by…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-19 Tao Zhu , Anzhong Wang , Gerald Cleaver , Klaus Kirsten , Qin Sheng

The previously proposed class of phenomenological inflationary models in which the assumption of inflaton slow-roll is replaced by the more general, constant-roll condition is compared with the most recent cosmological observational data,…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-28 Hayato Motohashi , Alexei A. Starobinsky