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Related papers: Trispectrum versus Bispectrum in Single-Field Infl…

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We perform the analysis of the trispectrum of curvature perturbations generated by the interactions characterizing a general theory of single-field inflation obtained by effective field theory methods. We find that curvature-generated…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Nicola Bartolo , Matteo Fasiello , Sabino Matarrese , Antonio Riotto

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

In this paper, we present a non-Gaussianity consistency relation that enables the calculation of the squeezed limit bispectrum of the curvature perturbation in single-field inflationary models by carefully inspecting the background…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-22 Mohammad Hossein Namjoo

Inflation creates perturbations for the large scale structures in the universe, but it also dilutes everything. Therefore it is pertinent that the end of inflation must explain how to excite the Standard Model {\it dof} along with the dark…

High Energy Physics - Phenomenology · Physics 2013-07-22 Lingfei Wang , Ernestas Pukartas , Anupam Mazumdar

In this paper we will discuss analytically the perturbations created from a slowly rolling subdominant spectator field which decays much before the end of inflation. The quantum fluctuations of such a spectator field can seed perturbations…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-25 Lingfei Wang , Anupam Mazumdar

We show how the primordial bispectrum of density perturbations from inflation may be characterised in terms of manifestly gauge-invariant cosmological perturbations at second order. The primordial metric perturbation, zeta, describing the…

Astrophysics · Physics 2009-11-13 Laura E. Allen , Sujata Gupta , David Wands

We show that there are inflationary models for which perturbations in the energy momentum tensor, which are of second order in the scalar field, cannot be neglected. We first specify the conditions under which the usual first order…

Astrophysics · Physics 2009-10-22 R. Durrer , M. Sakellariadou

We develop an integral form for the bispectrum in general single-field inflation whose domain of validity includes models of inflation where the background evolution is not constrained to be slowly varying everywhere. Our integral form…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 Peter Adshead , Wayne Hu , V Miranda

We calculate the trispectrum of curvature perturbations for a model of inflation endowed with Galilean symmetry at the level of the fluctuations around an FRW background. Such a model has been shown to posses desirable properties such as…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Nicola Bartolo , Emanuela Dimastrogiovanni , Matteo Fasiello

We present a detailed study of the trispectrum of the curvature perturbation generated within a stable, well defined and predictive theory which comprises an inflationary phase. In this model the usual shift symmetry is enhanced up to the…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-18 Frederico Arroja , Nicola Bartolo , Emanuela Dimastrogiovanni , Matteo Fasiello

We propose a model of inflation driven by the relaxation of an initially Planckian cosmological constant due to diffusion. The model can generate a (approximately) scale invariant spectrum of (adiabatic) primordial perturbations with the…

General Relativity and Quantum Cosmology · Physics 2022-10-05 Lautaro Amadei , Alejandro Perez

We calculate the trispectrum T_\zeta of the primordial curvature perturbation \zeta, generated during a {\it slow-roll} inflationary epoch by considering a two-field quadratic model of inflation with {\it canonical} kinetic terms. We…

Astrophysics · Physics 2010-04-15 Yeinzon Rodriguez , Cesar A. Valenzuela-Toledo

In most current models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, the period of inflation lasts so long that, at the beginning of the inflationary period, the physical wavelengths of…

High Energy Physics - Theory · Physics 2008-11-26 Jerome Martin , Robert H. Brandenberger

One-loop correction to the power spectrum in generic single-field inflation is calculated by using standard perturbation theory. Because of the enhancement inversely proportional to the observed red tilt of the spectral index of curvature…

High Energy Physics - Theory · Physics 2022-02-11 Jason Kristiano , Jun'ichi Yokoyama

We propose a new mechanism to generate primordial curvature perturbations, based on the resonant production of particles during inflation. It is known that this phenomenon can trap the inflaton for a fraction of e-fold. This effect is…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-17 David Langlois , Lorenzo Sorbo

Inflation offers a simple model for very early evolution of our Universe and the origin of primordial perturbations on large scales. Over the last 25 years we have become familiar with the predictions of single-field models, but inflation…

Astrophysics · Physics 2008-11-26 David Wands

The scale--independence of the primordial curvature perturbation suggests that it comes from the vacuum fluctuation during inflation of a light scalar field. This field may be the inflaton, or a different `curvaton' field. The observation…

High Energy Physics - Phenomenology · Physics 2007-05-23 David H. Lyth

We present a new class of two-field inflationary attractor models, known as `shift-symmetric orbital inflation', whose behaviour is strongly multi-field but whose predictions are remarkably close to those of single-field inflation. In these…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-29 Ana Achúcarro , Edmund J. Copeland , Oksana Iarygina , Gonzalo A. Palma , Dong-Gang Wang , Yvette Welling

We calculate the general solutions for a warm inflationary scenario with weak dissipation, reviewing the dissipative dynamics of the two-fluid system, and calculate the bispectrum of the gravitational field fluctuations generated in the…

Astrophysics · Physics 2008-11-26 Sujata Gupta

We study non-Gaussianities in the primordial perturbations in single field inflation where there is radiation era prior to inflation. Inflation takes place when the energy density of radiation drops below the value of the potential of a…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-30 Suratna Das , Subhendra Mohanty