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

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Inflation predicts the generation of cosmological perturbations. Usually, the power spectra for the scalar and tensor modes are calculated with help of the slow roll approximation. In the case of power law inflation an exact result is…

Astrophysics · Physics 2007-05-23 Dominik J. Schwarz , Jerome Martin

We investigate an ability of the exponential power-law inflation to be phenomenologically correct model of the early universe. GR scalar cosmology equations we study in Ivanov-Salopek-Bond (or Hamilton-Jacobi like) representation where the…

General Relativity and Quantum Cosmology · Physics 2025-01-22 I. V. Fomin , S. V. Chervon

We investigate the cosmic inflation within a class of the scalar-tensor model with the scalar-dependent non-minimal kinetic couplings. The inflationary dynamical potential will be applied. Using the slow-roll approximation, we compute…

General Relativity and Quantum Cosmology · Physics 2025-12-01 Feyzollah Younesizadeh , Davoud Kamani

We discuss the cosmological inflation in the context of $f(Q)$ non-metric gravity, where $Q$ is the non-metric scalar. After introducing conformal transformations for $f(Q)$ gravity, we first focus on the potential-slow-roll inflation by…

General Relativity and Quantum Cosmology · Physics 2022-09-23 Salvatore Capozziello , Mehdi Shokri

Slow-roll inflation may simultaneously solve the horizon problem and generate a near scale-free fluctuation spectrum P(k). These two processes are intimately connected via the initiation and duration of the inflationary phase. But a recent…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-03 Jingwei Liu , Fulvio Melia

We study the modifications induced on scalar field inflation produced by considering a general modification of the Heisenberg algebra. We proceed by modifying the Poisson brackets on the classical theory whenever the corresponding quantum…

General Relativity and Quantum Cosmology · Physics 2024-08-13 H. Garcia-Compean , D. Mata-Pacheco

We investigate inflation in closed Friedmann-Robertson-Walker universe filled with the scalar field with power-law potential. For a wide range of powers and parameters of the potential we numerically calculated the slow-roll parameters and…

Astrophysics · Physics 2009-11-16 S. A. Pavluchenko

In this paper we perform a global analysis of the constraints on the inflationary parameters in the presence of dynamical dark energy models from the current observations, including the three-year Wilkinson Microwave Anisotropy Probe…

Astrophysics · Physics 2008-11-26 Jun-Qing Xia , Xinmin Zhang

We add a thermal noise to Starobinsky equation of slow roll inflation. We calculate the number of e-folds of the stochastic system. The power spectrum and the spectral index are evaluated from the fluctuations of e-folds using an expansion…

General Relativity and Quantum Cosmology · Physics 2018-08-01 Z. Haba

We consider Einstein-Gauss-Bonnet (EGB) inflationary models using the effective potential approach. We present evolution equations in the slow-roll regime using the effective potential and the tensor-to-scalar ratio. The choice of the…

General Relativity and Quantum Cosmology · Physics 2021-06-30 Ekaterina O. Pozdeeva

We argue that the non-detection of primordial tensor modes has taught us a great deal about the primordial universe. In single-field slow-roll inflation, the current upper bound on the tensor-to-scalar ratio, $r < 0.07$ $(95 \% ~CL)$,…

High Energy Physics - Theory · Physics 2017-06-21 Enrico Pajer , Guilherme L. Pimentel , Jaap V. S. Van Wijck

We propose a new way to implement an inflationary prior to a cosmological dataset that incorporates the inflationary observables at arbitrary order. This approach employs an exponential form for the Hubble parameter $H(\phi)$ without taking…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Daniel Wohns , Jiajun Xu , S. -H. Henry Tye

We consider a model of two-field inflation, containing an ordinary scalar field and a DBI field. We work beyond the slow-roll approximation, but we assume a separable Hubble parameter. We then derive the form of potential in this framework…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-25 Kourosh Nozari , Kosar Asadi

We consider slow-roll inflation in the context of recently proposed four-dimensional effective gravity induced on the world-volume of a three-brane in five-dimensional Einstein gravity. We find significant modifications of the simplest…

High Energy Physics - Phenomenology · Physics 2009-12-30 R Maartens , D Wands , B Bassett , I Heard

The most current observational data corroborate the Starobinsky model as one of the strongest candidates in the description of an inflationary regime. Motivated by such success, extensions of the Starobinsky model have been increasingly…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-14 G. Rodrigues-da-Silva , J. Bezerra-Sobrinho , L. G. Medeiros

This paper focuses on the Starobinsky model of inflation. We derive solutions for various cosmological observables, such as the scalar spectral index $n_s$, the tensor-to-scalar ratio $r$ and their runnings, as well as the number of…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-22 Gabriel German , Juan Carlos Hidalgo , Luis E. Padilla

The aim of this paper is to provide a more precise description of the paradigm of corpuscular slow-roll inflation, which was previously introduced by Casadio et al. in [1]. Specifically, we start by expanding the Starobinsky theory on a…

General Relativity and Quantum Cosmology · Physics 2019-09-04 Andrea Giugno , Andrea Giusti

One common approach for cosmic inflation consists in couple Einstein's gravity with a scalar field, often referred to inflaton field. In order to derive analytic simple scenarios, we usually work in the {\it slow-roll} regime. In such an…

General Relativity and Quantum Cosmology · Physics 2021-01-01 J. R. L. Santos , P. H. R. S. Moraes

The reconstruction of an inflationary universe considering the parametrization of the scalar spectral index as a function of the number of $e-$folds in the framework of a modified Friedmann equation is analyzed. In this context, we examine…

General Relativity and Quantum Cosmology · Physics 2024-09-12 Ramon Herrera , Carlos Rios

Inflationary predictions for the anisotropy of the cosmic microwave background radiation (CMBR) are often based on the slow-roll approximation. We study the precision with which the multipole moments of the temperature two-point correlation…

Astrophysics · Physics 2009-10-31 Jerome Martin , Dominik Schwarz
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