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Thermal fluctuations provide the main source of large scale density perturbations in warm inflationary models of the early universe. For the first time, general results are obtained for the power spectrum in the case when the friction…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-28 Chris Graham , Ian G Moss

It was recently shown that a large value of the tensor to scalar ratio $r$ implies a constraint on the minimum value of the sound speed $c_s$ of primordial curvature perturbations during inflation that is stronger than current bounds coming…

High Energy Physics - Theory · Physics 2015-07-06 Gonzalo A. Palma , Alex Soto

We study the intermediate inflation scenario in the context of $F(T)$ gravity, and we examine it's viability by calculating the power spectrum of the primordial curvature perturbations and the corresponding spectral index. As we…

General Relativity and Quantum Cosmology · Physics 2017-04-26 V. K. Oikonomou

In this paper we quantise scalar perturbations in a Randall-Sundrum-type model of inflation where the inflaton field is confined to a single brane embedded in five-dimensional anti-de Sitter space-time. In the high energy regime,…

High Energy Physics - Theory · Physics 2010-10-27 Kazuya Koyama , Andrew Mennim , V. A. Rubakov , David Wands , Takashi Hiramatsu

We compute all N-point primordial curvature correlation functions from inflation at tree-level up to N of order ten or more depending on the choice of parameters. This is achieved for resonant inflationary models in which the inflaton…

High Energy Physics - Theory · Physics 2011-05-31 Louis Leblond , Enrico Pajer

A new model of inflation is described. An unusual form for the inflationary potential is obtained because the inflaton corresponds to a non-trivial path in the configuration space of the two real scalar fields of the model. The model…

Astrophysics · Physics 2009-10-22 Ewan D. Stewart

There are several works searching for a clue of trans-Planckian physics on the primordial density perturbation spectrum. Here we would like to point out an important aspect which has been overlooked so far. When we consider a model in which…

Astrophysics · Physics 2007-05-23 Takahiro Tanaka

I investigate multi-field inflationary models with fields that decay during inflation, leading to staggered inflation. This feature is natural in many models motivated by string theory, for instance if inflatons are related to interbrane…

Astrophysics · Physics 2010-01-08 Thorsten Battefeld

We set up a formalism that can be used to calculate the power spectrum of the curvature perturbations produced during inflation up to arbitrary order in the slow-roll expansion, and explicitly calculate the power spectrum and spectral index…

Astrophysics · Physics 2009-11-06 Ewan D. Stewart , Jin-Ook Gong

We explore the observational implications of models of intermediate inflation driven by modified dispersion relations, specifically those representing the phenomenon of dimensional reduction in the ultraviolet limit. These models are…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-23 John D. Barrow , Macarena Lagos , João Magueijo

This is a review of particle-theory models of inflation, and of their predictions for the primordial density perturbation that is thought to be the origin of structure in the Universe. It contains mini-reviews of the relevant observational…

High Energy Physics - Phenomenology · Physics 2009-06-19 David H. Lyth , Antonio Riotto

Effects caused by an additional massive scalar field interacting with an inflaton field are analyzed. Inflation is shown to have two stages, the first of which is dominant and characterized by ultraslow dynamics of the inflaton field.…

High Energy Physics - Phenomenology · Physics 2014-11-17 S. G. Rubin

We revisit the study of the phenomenology associated to a burst of particle production of a field whose mass is controlled by the inflaton field and vanishes at one given instance during inflation. This generates a bump in the correlators…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-14 Lauren Pearce , Marco Peloso , Lorenzo Sorbo

We explore the homogeneous background dynamics and the evolution of generated perturbations of cosmological inflation that is driven by multiple scalar fields interacting with a perfect fluid.Then we apply the method to warm inflation…

General Relativity and Quantum Cosmology · Physics 2018-04-04 Yang-Yang Wang , Jian-Yang Zhu , Xiao-Min Zhang

Inflation models can have an early phase of inflation where the evolution of the inflaton is driven by quantum fluctuations before entering the phase driven by the slope of the scalar field potential. For a Coleman-Weinberg potential this…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-06 Arjun Berera , Raghavan Rangarajan

We propose one way to regularize the fluctuations generated during inflation, whose infrared (IR) corrections diverge logarithmically. In the case of a single field inflation model, recently, we proposed one solution to the IR divergence…

High Energy Physics - Theory · Physics 2010-02-02 Yuko Urakawa , Takahiro Tanaka

Until recently our knowledge of the primordial curvature perturbation was relatively modest. Ever since COBE delivered its map of data we know the scalar spectrum of primordial perturbations is approximately flat, with the power being only…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-24 Raquel H. Ribeiro

We investigate the phenomenology of warm inflation and present generic results about the evolution of the inflaton and radiation fields. The general conditions required for warm inflation to take place are derived and discussed. A…

Astrophysics · Physics 2009-10-31 A. N. Taylor , A. Berera

In this work, we analytically calculate the spectra of primordial perturbations at the end of Type III hilltop inflation models under the slow-roll approximation. We examine the one-loop corrections of the spectra and find that those from…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-04 Chia-Min Lin , Da-Shin Lee

We study slow-roll inflation on a three-brane in a five-dimensional bulk where the effects of energy loss from the brane due to graviton emission is included in a self-consistent manner. We explicitly derive the form of the energy loss term…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-07 Ashok Thillaisundaram