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Related papers: Non-Gaussianity Unleashed

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Scalar field cosmological inflation has a first integral relating the Hubble function and the lagrangian of the scalar field(s), which is known under the names of "Hamilton-Jacobi approach" or "superpotential equation". Here we exploit the…

General Relativity and Quantum Cosmology · Physics 2019-07-09 C. Adam , D. Varela

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 compute the super-Hubble evolution of non-Gaussianity of primordial curvature perturbations in two-field inflation models by employing two formalisms: delta N and covariant formalisms. Although two formalisms treat the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Yuki Watanabe

In the scenario of single-field inflation, this field is done in terms of Jacobian elliptic functions. This approach provides, when constrained to particular cases, analytic solutions already known in the past, generalizing them to a bigger…

General Relativity and Quantum Cosmology · Physics 2015-06-11 J. R. Villanueva , Emanuel Gallo

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

Using Hamilton-Jacobi formalism, The scenario of warm inflation with viscous pressure is considered. The formalism gives a way of computing the slow-rolling parameters without extra approximation, and it is well-known as a powerful method…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-17 L. Akhtari , A. Mohammadi , K. Sayar , Kh. Saaidi

Quantization implies independent degrees of freedom that do not appear in the classical theory, given by fluctuations, correlations, and higher moments of a state. A systematic derivation of the resulting dynamical systems is presented here…

High Energy Physics - Theory · Physics 2021-08-24 Martin Bojowald , Suddhasattwa Brahma , Sean Crowe , Ding Ding , Joseph McCracken

The general expression for the second order large scale curvature perturbation in the form of a functional over a background solution is derived. The explicit expressions was obtained for two special forms of the inflationary potential. In…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-26 N. A. Koshelev

In this article, we show that a stochastic form of scale-dependent halo bias arises in multi-source inflationary models, where multiple fields determine the initial curvature perturbation. We derive this effect for general non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-14 Daniel Baumann , Simone Ferraro , Daniel Green , Kendrick M. Smith

We study the scalar-tensor-tensor non-Gaussian signal in an inflationary model comprising also an axion coupled with SU(2) gauge fields. In this set-up, metric fluctuations are sourced by the gauge fields already at the linear level…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-28 Emanuela Dimastrogiovanni , Matteo Fasiello , Robert J. Hardwick , Hooshyar Assadullahi , Kazuya Koyama , David Wands

For simple inflationary models, we provide a consistent and complete scheme by which the macro-physical details of early universe inflation may be determined explicitly from the underlying micro-physical theory. We examine inflationary…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Cormier

We compute the three-point correlation function of primordial scalar density perturbations in a general single-field inflationary scenario, where a scalar field phi has a direct coupling with the Ricci scalar R and the Gauss-Bonnet term GB.…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-22 Antonio De Felice , Shinji Tsujikawa

Multiple inflation is a model based on N=1 supergravity wherein there are sudden changes in the mass of the inflaton because it couples to 'flat direction' scalar fields which undergo symmetry breaking phase transitions as the universe…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Shaun Hotchkiss , Subir Sarkar

We compute the covariant three-point function near horizon-crossing for a system of slowly-rolling scalar fields during an inflationary epoch, allowing for an arbitrary field-space metric. We show explicitly how to compute its subsequent…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-10 Joseph Elliston , David Seery , Reza Tavakol

We introduce a frame-covariant formalism for inflation of scalar-curvature theories by adopting a differential geometric approach which treats the scalar fields as coordinates living on a field-space manifold. This ensures that our…

High Energy Physics - Phenomenology · Physics 2018-01-09 Sotirios Karamitsos , Apostolos Pilaftsis

We present an estimate for the non-linear parameter \tau_NL, which measures the non-gaussianity imprinted in the trispectrum of the comoving curvature perturbation, \zeta. Our estimate is valid throughout the inflationary era, until the…

Astrophysics · Physics 2010-10-27 David Seery , James E. Lidsey

We consider a class of multi-component hybrid inflation models whose evolution may be analytically solved under the slow-roll approximation. We call it multi-brid inflation (or $n$-brid inflation where $n$ stands for the number of inflaton…

Astrophysics · Physics 2009-10-09 Misao Sasaki

We study the slow-roll inflation models, where the inflaton slow-rolls along a trajectory whose orthogonal directions are lifted by potentials with masses of order the Hubble parameter. In these models large non-Gaussianities can be…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Xingang Chen , Yi Wang

We show that theories of inflation with multiple, rapidly turning fields can generate large amounts of non-Gaussianity. We consider a general theory with two fields, an arbitrary field-space metric, and a potential that supports sustained,…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-21 Oksana Iarygina , M. C. David Marsh , Gustavo Salinas

Recent studies of inflation with multiple scalar fields have highlighted the importance of non-canonical kinetic terms in novel types of inflationary solutions. This motivates a thorough analysis of non-Gaussianities in this context, which…

High Energy Physics - Theory · Physics 2020-02-11 Sebastian Garcia-Saenz , Lucas Pinol , Sébastien Renaux-Petel