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The effect of pre-inflation physics on the power spectrum of scalar perturbations is estimated and there is a possibility that the pre-inflation physics explains the Wilkinson Microwave Anisotropy Probe data if the length of inflation is…

Astrophysics · Physics 2007-05-23 Shiro Hirai

Cosmic inflation, which describes an accelerated expansion of the early Universe, yields the most successful predictions regarding temperature anisotropies in the cosmic microwave background (CMB). Nevertheless, the precise origin of the…

General Relativity and Quantum Cosmology · Physics 2020-08-14 Gabriel Leon , Maria Pia Piccirilli

[Abridged] The primordial scalar power spectrum is well constrained on large scales, primarily by the observations of the anisotropies in the cosmic microwave background (CMB). Over the last few years, it has been recognized that a sharp…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-21 H. V. Ragavendra , Pankaj Saha , L. Sriramkumar , Joseph Silk

The aim of this paper is to probe the features of the bouncing cosmology with the current observational data. Basing on bounce inflation model, with high derivative term, we propose a general parametrization of primordial power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-07 Shulei Ni , Hong Li , Taotao Qiu , Wei Zheng , Xin Zhang

We analyse the dynamics of spinodal decomposition in inflationary cosmology using the closed time path formalism of out of equilibrium quantum field theory combined with the non-perturbative Hartree approximation. In addition to a general…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. Cormier , R. Holman

The latest analysis of the cosmic microwave background by the Planck team finds more smoothing of the acoustic peaks in the temperature power spectrum than predicted by $\Lambda$CDM. Here we investigate whether this additional smoothing can…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-18 Guillem Domènech , Marc Kamionkowski

We derive some new constraints on single-field inflation from the Wilkinson Microwave Anisotropy Probe 3-year data combined with the Sloan Luminous Red Galaxy survey. Our work differs from previous analyses by focusing only on the…

Astrophysics · Physics 2008-11-26 Julien Lesgourgues , Wessel Valkenburg

We present new constraints on possible features in the primordial inflationary density perturbations power spectrum in light of the recent Cosmic Microwave Background Anisotropies measurements from the Planck satellite. We found that the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Micol Benetti

Brief periods of non-slow-roll evolution during inflation can produce interesting observable consequences, as primordial black holes, or an inflationary gravitational wave spectrum enhanced at small scales. We develop a model independent,…

High Energy Physics - Theory · Physics 2021-06-29 Gianmassimo Tasinato

I examine the status of inflationary cosmology in light of the first-year data from the WMAP satellite, focusing on the simplest models of inflation: those driven by a single scalar field. The WMAP observation of the Cosmic Microwave…

Astrophysics · Physics 2007-05-23 William H. Kinney

In view of recent interest in high-frequency detectors, broad features of gravitational wave signals from phase transitions taking place soon after inflation are summarized. The influence of the matter domination era that follows the…

General Relativity and Quantum Cosmology · Physics 2024-03-14 H. Kolesova , M. Laine

We place functional constraints on the shape of the inflaton potential from the cosmic microwave background through a variant of the generalized slow roll approximation that allows large amplitude, rapidly changing deviations from…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-01 Cora Dvorkin , Wayne Hu

It is well known that damped superimposed oscillations at large scales in the primordial power spectrum can be generated in both single field and two field models. In single field inflationary models, these features typically arise due to…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-27 Anvy Moly Tom , Rathul Nath Raveendran

Recent fits of cosmological parameters by the first year Wilkinson Microwave Anisotropy Probe (WMAP) measurement seem to favor a primordial scalar spectrum with a large varying index from blue to red. We use the inflationary flow equations…

Astrophysics · Physics 2009-11-10 Chiyi Chen , Bo Feng , Xiulian Wang , Zhaoyu Yang

Warm inflation model with bulk viscous pressure in the context of "intermediate inflation" where the cosmological scale factor expands as $a(t)=a_0\exp(At^f)$, is studied. The characteristics of this model in slow-roll approximation and in…

General Relativity and Quantum Cosmology · Physics 2015-06-18 M. R. Setare , V. Kamali

The impact of particle production during inflation on the primordial curvature perturbation spectrum is investigated both analytically and numerically. We obtain an oscillatory behavior on small scales, while on large scales the spectrum is…

General Relativity and Quantum Cosmology · Physics 2009-02-23 Antonio Enea Romano , Misao Sasaki

We clarify classical inflaton models by considering them as effective field theories `a la Ginzburg-Landau. In this approach, the WMAP statement excluding the pure phi^4 potential implies the presence of an inflaton mass term at the scale m…

Astrophysics · Physics 2009-11-10 D. Boyanovsky , H. J. de Vega , N. G. Sanchez

We calculate the power spectrum of metric fluctuations in inflationary cosmology starting with initial conditions which are imposed mode by mode when the wavelength equals some critical length $\ell_{_{\rm C}}$ corresponding to a new energy…

High Energy Physics - Theory · Physics 2009-11-10 Jerome Martin , R. H. Brandenberger

Oscillons are massive, long-lived, localized excitations of a scalar field. We show that in a large class of well-motivated single-field models, inflation is followed by self-resonance, leading to copious oscillon generation and a lengthy…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-09 Mustafa A. Amin , Richard Easther , Hal Finkel , Raphael Flauger , Mark P. Hertzberg

A smooth inflaton potential is generally assumed when calculating the primordial power spectrum, implicitly assuming that a very small oscillation in the inflaton potential creates a negligible change in the predicted halo mass function. We…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 Luiz Felippe S. Rodrigues , Reuven Opher