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Related papers: Non-Gaussianity in Two-Field Inflation

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In this work, we present a method for implementing the $\delta N$ formalism to study the primordial non-Gaussianity produced in multiple three-form field inflation. Using a dual description relating three-form fields to noncanonical scalar…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-09 K. Sravan Kumar , David J. Mulryne , Nelson J. Nunes , João Marto , Paulo Vargas Moniz

We study the bispectrum of the curvature perturbation on uniform energy density hypersurfaces in models of inflation with two scalar fields evolving simultaneously. In the case of a separable potential, it is possible to compute the…

Astrophysics · Physics 2009-11-11 Filippo Vernizzi , David Wands

We review models which generate a large non-Gaussianity of the local form. We first briefly consider three models which generate the non-Gaussianity either at or after the end of inflation; the curvaton scenario, modulated (p)reheating and…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Christian T. Byrnes , Ki-Young Choi

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

We investigate non-Gaussianity in general multiple-field inflation using the formalism we developed in earlier papers. We use a perturbative expansion of the non-linear equations to calculate the three-point correlator of the curvature…

Astrophysics · Physics 2009-11-13 G. I. Rigopoulos , E. P. S. Shellard , B. J. W. van Tent

We use the long-wavelength formalism to compute the bispectral non-Gaussianity produced in two-field inflation. We find an exact result that is used as the basis of numerical studies, and an explicit analytical slow-roll expression for…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Eleftheria Tzavara , Bartjan van Tent

We study the generation of non-Gaussianity in models of hybrid inflation with two inflaton fields, (2-brid inflation). We analyse the region in the parameter and the initial condition space where a large non-Gaussianity may be generated…

Astrophysics · Physics 2010-04-30 Christian T. Byrnes , Ki-Young Choi , Lisa M. H. Hall

After simplifying and improving the non-Gaussian formalism we developed in previous work, we derive a quantitative expression for the three-point correlator (bispectrum) of the curvature perturbation in general multiple-field inflation…

Astrophysics · Physics 2008-11-26 G. I. Rigopoulos , E. P. S. Shellard , B. J. W. van Tent

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 use the long-wavelength formalism to investigate the level of bispectral non-Gaussianity produced in two-field inflation models with standard kinetic terms. Even though the Planck satellite has so far not detected any primordial…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-17 Gabriel Jung , Bartjan van Tent

We study the non-Gaussianity generated during multiple-field inflation. We provide an exact expression for the bispectrum parameter f_NL which is valid beyond the slow-roll regime, valid for certain classes of inflationary models. We then…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-04 Christian T. Byrnes , Gianmassimo Tasinato

Focusing on the local type primordial non-Gaussianities, we study the bispectrum and trispectrum during a non-minimal slow-roll inflation. We use the so-called $\delta N$ formalism to investigate the super-horizon evolution of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-28 Kosar Asadi , Kourosh Nozari

While detection of the "local form" bispectrum of primordial perturbations would rule out all single-field inflation models, multi-field models would still be allowed. We show that multi-field models described by the $\delta N$ formalism…

General Relativity and Quantum Cosmology · Physics 2011-07-28 Naonori S. Sugiyama , Eiichiro Komatsu , Toshifumi Futamase

We calculate the conditions required to produce a large local trispectrum during two-field slow-roll inflation. This is done by extending and simplifying the 'heatmap' approach developed by Byrnes et al. The conditions required to generate…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-10 Joseph Elliston , Laila Alabidi , Ian Huston , David J. Mulryne , Reza Tavakol

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

In this paper we mainly focus on the curvature perturbation generated at the end of multi-field inflation, such as the multi-brid inflation. Since the curvature perturbation is produced on the super-horizon scale, the bispectrum and…

High Energy Physics - Theory · Physics 2010-04-15 Qing-Guo Huang

We compute analytic expressions for the non-linearity parameters characterizing the bi- and tri-spectrum of primordial curvature perturbations generated during an inflationary epoch of the early universe driven by an arbitrary number of…

High Energy Physics - Theory · Physics 2011-11-04 Diana Battefeld , Thorsten Battefeld

We compute the amplitude of the non-Gaussianities in inflationary models with multiple, uncoupled scalar fields. This calculation thus applies to all models of assisted inflation, including N-flation, where inflation is driven by multiple…

Astrophysics · Physics 2010-10-27 Thorsten Battefeld , Richard Easther

We find constraints on inflationary dynamics that yield a large local bispectrum and/or trispectrum during two-field slow-roll inflation. This leads to simple relations between the non-Gaussianity parameters, simplifying the…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-21 Joseph Elliston

Using the "$\delta N$-formalism", We obtain the expression of the non-Gaussianity of multiple-field inflationary models with the nontrivial field-space metric. Further, we rewritten the result by using the slow-rolling approximation.

Astrophysics · Physics 2009-11-11 C. Y. Sun , D. H. Zhang
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