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In this work, we analyze a power-law inflationary potential enhanced with a step that can introduce features in the primordial power spectrum. We focus on the computation of the Spectral Distortions (SD) induced by these features obtained…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-27 Jorge Mastache , Wilson Barrera , Raúl Henríquez-Ortiz

We study the background dynamics and primordial perturbation in $\alpha$-attractor-type double inflation. The model is composed of two minimally coupled scalar fields, where each of the fields has a potential of the $\alpha$-attractor type.…

High Energy Physics - Theory · Physics 2019-01-09 Kei-ichi Maeda , Shuntaro Mizuno , Ryota Tozuka

We study non-linear primordial adiabatic and isocurvature perturbations and their non-Gaussianity. After giving a general formulation in the context of an extended delta N-formalism, we analyse in detail two illustrative examples. The first…

Astrophysics · Physics 2010-04-30 David Langlois , Filippo Vernizzi , David Wands

We re-analyse current single-field inflationary models related to primordial black holes formation. We do so by taking into account recent developments on the estimations of their abundances and the influence of non-gaussianities. We show…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-14 Vicente Atal , Cristiano Germani

Inflationary cosmology proposes that the early Universe undergoes accelerated expansion, driven, in simple scenarios, by a single scalar field, or inflaton. The form of the inflaton potential determines the initial spectra of density…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Richard Easther , Benedict Bahr-Kalus , David Parkinson

The generic prediction for the perturbations generated during slow--roll, single--field inflation, as they appear in the cosmic microwave background (CMB), is a flat, close--to--Gaussian spectrum. We calculate the general solution for a…

Astrophysics · Physics 2007-05-23 S. Gupta

The curvaton and the inhomogeneous reheating scenarios for the generation of the cosmological curvature perturbation on large scales represent an alternative to the standard slow-roll scenario where the observed density perturbations are…

Astrophysics · Physics 2009-11-10 L. Pilo , A. Riotto , A. Zaffaroni

We study the problem of initial conditions for slow-roll inflation along a plateau-like scalar potential within the framework of fluctuation-dissipation dynamics. We consider, in particular, that inflation was preceded by a…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-09 Mar Bastero-Gil , Arjun Berera , Robert Brandenberger , Ian G. Moss , Rudnei O. Ramos , Joao G. Rosa

Primordial perturbations with wavelengths greater than the observable universe shift the effective background fields in our observable patch from their global averages over the inflating space. This leads to a landscape picture where the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Sami Nurmi , Christian T. Byrnes , Gianmassimo Tasinato

We discuss features of the inflaton potential that can lead to a strong enhancement of the power spectrum of curvature perturbations. We show that a steep decrease of the potential induces an enhancement of the spectrum by several orders of…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 K. Kefala , G. P. Kodaxis , I. D. Stamou , N. Tetradis

Many statistics available to constrain non-Gaussianity from inflation are simplest to use under the assumption that the curvature correlation functions are hierarchical. That is, if the n-point function is proportional to the (n-1) power of…

Astrophysics · Physics 2010-04-30 Sarah Shandera

We obtain the effective inflaton potential during slow roll inflation by including the one loop quantum corrections to the energy momentum tensor from scalar curvature and tensor perturbations as well as quantum fluctuations from light…

Astrophysics · Physics 2009-11-13 D. Boyanovsky , H. J. de Vega , N. G. Sanchez

This article investigates the generation of non-Gaussianity during inflation. In the context of multi-field inflation, we detail a mechanism that can create significant primordial non-Gaussianities in the adiabatic mode while preserving the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Francis Bernardeau , Jean-Philippe Uzan

We have studied modulated inflation that generates curvature perturbation from light-field fluctuation. As discussed in previous works, even if the fluctuation of the inflaton itself does not generate the curvature perturbation at the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Tomohiro Matsuda

We carry out a comprehensive analysis of the simplest curvaton model, which is based on two non-interacting massive fields. Our analysis encompasses cases where the inflaton and curvaton both contribute to observable perturbations, and…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-13 Christian T. Byrnes , Marina Cortês , Andrew R. Liddle

Inflation is a highly favoured theory for the early Universe. It is compatible with current observations of the cosmic microwave background and large scale structure and is a driver in the quest to detect primordial gravitational waves. It…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-19 Tomás Sousa , Deaglan J. Bartlett , Harry Desmond , Pedro G. Ferreira

Stochastic effects in generic scenarios of inflation with multiple fields are investigated. First passage time techniques are employed to calculate the statistical moments of the number of inflationary $e$-folds, which give rise to all…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Vincent Vennin , Hooshyar Assadullahi , Hassan Firouzjahi , Mahdiyar Noorbala , David Wands

We suggest a new method to reconstruct, within canonical single-field inflation, the inflaton potential directly from the primordial power spectrum which may deviate significantly from near scale-invariance. Our approach relies on a more…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-12 Ki-Young Choi , Jinn-Ouk Gong , Su-beom Kang , Rathul Nath Raveendran

We have developed a precise dictionary between the spectrum of primordial density fluctuations and the parameters of the effective field theory (EFT) of inflation that determine the primordial power spectrum (PPS). At lowest order the EFT…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-15 Amel Durakovic

We consider a curvaton scenario in which the late-time domination and the generation of the curvature perturbation is achieved by a non-oscillatory (NO) curvaton potential. Instead of considering the conventional curvaton oscillation, we…

High Energy Physics - Phenomenology · Physics 2008-11-26 Tomohiro Matsuda
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