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Related papers: Inflation over the hill

200 papers

We study (p)reheating in alpha-attractor T-models of inflation, taking into account both scalar fields present in these models: the inflaton and the spectator. The two-field model has a negative field-space curvature which, at the end of…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-04 Tomasz Krajewski , Krzysztof Turzyński , Michał Wieczorek

We study non-linear contributions to the power spectrum of the curvature perturbation on super-horizon scales, produced during slow-roll inflation driven by a canonical single scalar field. We find that on large scales the linear power…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Jinn-Ouk Gong , Hyerim Noh , Jai-chan Hwang

The single scalar field inflationary models that lead to scalar and tensor perturbation spectra with amplitudes varying in direct proportion to one another are reconstructed by solving the Stewart-Lyth inverse problem to next-to-leading…

Astrophysics · Physics 2009-11-07 C. A. Terrero-Escalante , James E. Lidsey , Alberto A. Garcia

We elucidate the counting of the relevant small parameters in inflationary perturbation theory. Doing this allows for an explicit delineation of the domain of validity of the semi-classical approximation to gravity used in the calculation…

High Energy Physics - Theory · Physics 2018-02-21 Peter Adshead , C. P. Burgess , R. Holman , Sarah Shandera

I examine the standard formalism of calculating curvature perturbations in inflation at horizon crossing, and derive a general relation which must be satisfied for the horizon crossing formalism to be valid. This relation is satisfied for…

General Relativity and Quantum Cosmology · Physics 2009-11-11 William H. Kinney

Precise cosmological data from WMAP and forthcoming CMB experiments motivate the study of the quantum corrections to the slowroll inflationary parameters.We find the quantum (loop) corrections to the equations of motion of the classical…

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

The inflaton field responsible for inflation may not be a canonical fundamental scalar. It is possible that the inflaton is a composite of fermions or it may have a decay width. In these cases the standard procedure for calculating the…

High Energy Physics - Phenomenology · Physics 2009-09-28 Suratna Das , Subhendra Mohanty

The inflaton equation of motion including one loop radiative corrections from spectator fields is obtained. We consider a massless scalar conformally coupled to gravity and a massless fermion Yukawa coupled to the inflaton as models for…

High Energy Physics - Phenomenology · Physics 2026-04-07 Daniel Boyanovsky

The background evolution in two-field inflation can feature two distinct stages, corresponding to the evolution along two successive field directions. When the second stage occurs at a significantly lower energy scale, the inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-23 I. Dalianis , A. Katsis , N. Tetradis

We develop a variant of the generalized slow roll approach for calculating the curvature power spectrum that is well-suited for order unity deviations in power caused by sharp features in the inflaton potential. As an example, we show that…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-07 Cora Dvorkin , Wayne Hu

We compute the power spectrum of super-horizon curvature perturbations generated during a late period of thermal inflation, taking into account fluctuation-dissipation effects resulting from the scalar flaton field's interactions with the…

High Energy Physics - Phenomenology · Physics 2024-07-22 Mar Bastero-Gil , Joaquim M. Gomes , João G. Rosa

In 'hilltop inflation', inflation takes place when the inflaton field slowly rolls from close to a maximum of its potential (i.e. the 'hilltop') towards its minimum. When the inflaton potential is associated with a phase transition,…

High Energy Physics - Phenomenology · Physics 2015-06-24 Stefan Antusch , David Nolde , Stefano Orani

Any one-field inflation is actually realized in a multifield configuration because the inflaton must have couplings with other fields to reheat the universe and is coupled to all other fields at least gravitationally. In all single inflaton…

High Energy Physics - Phenomenology · Physics 2009-11-11 Masahide Yamaguchi , Jun'ichi Yokoyama

If the inflaton is a heavy scalar field, it may equilibrate slower than some other degrees of freedom, e.g. non-Abelian gauge bosons. In this case, perturbations in the inflaton field and in a thermal plasma coexist from a given moment…

High Energy Physics - Phenomenology · Physics 2024-10-18 M. Laine , S. Procacci , A. Rogelj

There might be a light scalar field during inflation which is not responsible for the accelerating inflationary expansion. Then, its quantum fluctuation is stretched during inflation. This scalar field could be a curvaton, if it decays at a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Ki-Young Choi , Osamu Seto

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

Inflationary models involving more than one scalar field naturally produce isocurvature perturbations. However, while these are fairly well studied, less is known about their evolution through the reheating epoch, when the inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-03 Ian Huston , Adam J. Christopherson

We construct a multi-field inflationary model consisting of multiple K\"ahler moduli derived from type IIB string compactification in the large volume limit. The model consists of both heavy and light fields, with the former being frozen…

High Energy Physics - Theory · Physics 2009-12-09 Per Berglund , Guoqin Ren

We obtain cosmological constraints on models of inflation which exhibit rapid roll solutions. Rapid roll attractors exist for potentials with large mass terms and are thus of interest for inflationary model building within string theory. We…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-15 Takeshi Kobayashi , Shinji Mukohyama , Brian A. Powell

We show how observations of the perturbation spectra produced during inflation may be used to constrain the parameters of general scalar-tensor theories of gravity, which include both an inflaton and dilaton field. An interesting feature of…

General Relativity and Quantum Cosmology · Physics 2016-08-24 Juan Garcia-Bellido , David Wands