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Related papers: Large Non-Gaussianities in Single Field Inflation

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The methods of effective field theory are used to study generic theories of inflation with a single inflaton field and to perform a general analysis of the associated non-Gaussianities. We investigate the amplitudes and shapes of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Nicola Bartolo , Matteo Fasiello , Sabino Matarrese , Antonio Riotto

We investigate the primordial non-Gaussianities from the trispectra in multi-field inflation models, which can be seen as generalization of multi-field $k$-inflation and multi-DBI inflation. We derive the full fourth-order perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Xian Gao , Miao Li , Chunshan Lin

We compute the leading order contribution to the four-point function of the primordial curvature perturbation in a class of single field models where the inflationary Lagrangian is a general function of the inflaton and its first…

High Energy Physics - Theory · Physics 2008-12-04 Xingang Chen , Min-xin Huang , Gary Shiu

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 study a particular Galileon inflation in the light of Planck2015 observational data in order to constraint the model parameter space. We study the spectrum of the primordial modes of the density perturbations by expanding the action up…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-14 Kosar Asadi , Kourosh Nozari

For very general scalar-field theories in which the equations of motion are at second-order, we evaluate the three-point correlation function of primordial scalar perturbations generated during inflation. We show that the shape of…

General Relativity and Quantum Cosmology · Physics 2011-10-11 Antonio De Felice , Shinji Tsujikawa

The non-Gaussianity of inflationary perturbations, as encoded in the bispectrum (or 3-point correlator), has become an important additional way of distinguishing between inflation models, going beyond the linear Gaussian perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-23 Bartjan van Tent

These notes present a detailed introduction to Maldacena's calculation of the three-point function generated by the simplest class of inflationary models: those with a single inflaton field whose potential satisfies the slow-roll conditions…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-02 Hael Collins

We present a simple way to calculate non-Gaussianity in inflation using fully non-linear equations on long wavelengths with stochastic sources to take into account the short-wavelength quantum fluctuations. Our formalism includes both…

Astrophysics · Physics 2009-11-10 G. I. Rigopoulos , E. P. S. Shellard , B. J. W. van Tent

We construct models of inflation with many randomly interacting fields and use these to study the generation of cosmological observables. We model the potentials as multi-dimensional Gaussian random fields (GRFs) and identify powerful…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-28 Theodor Bjorkmo , M. C. David Marsh

Given the fantastic experimental effort, it is important to thoroughly explore the signature space of inflationary models. The fact that higher derivative operators do not renormalize lower derivative ones allows us to find a large class of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Siavosh R. Behbahani , Mehrdad Mirbabayi , Leonardo Senatore , Kendrick M. Smith

Using a principal component (PC) basis that accommodates order unity features in the slow roll parameters as fine as 1/10 of a decade across more than 2 decades of the inflationary expansion, we test slow roll and single field inflation…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Cora Dvorkin , Wayne Hu

This paper presents and investigates non-Gaussian perturbations for the warm k-inflation model that is driven by pure kinetic energy. The two complementary components of the overall non-Gaussianity are the three-point and four-point…

General Relativity and Quantum Cosmology · Physics 2025-11-21 Xiao-Min Zhang , Run-Qing Zhao , Yun-Cai Feng , Peng-Cheng Chu , Zhi-Peng Peng , Xi-Bin Li

We describe models of single-field inflation with small and sharp step features in the potential (and sound speed) of the inflaton field, in the context of the Effective Field Theory of Inflation. This approach allows us to study the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Nicola Bartolo , Dario Cannone , Sabino Matarrese

The Cosmic Microwave Background can provide information regarding physics of the very early universe, more specifically, of the matter-radiation distribution of the inflationary era. Starting from the effective field theory of inflation, we…

High Energy Physics - Theory · Physics 2015-09-02 Anindya Banerjee , Himanshu Khanchandani

We study nonlinear cosmological perturbations and their possible non-Gaussian character in an extended non-minimal inflation where gravity is coupled non-minimally to both the scalar field and its derivatives. By expansion of the action up…

General Relativity and Quantum Cosmology · Physics 2019-10-09 Raheleh Shojaee , Kourosh Nozari , Farhad Darabi

We perform a general study of the primordial scalar non-Gaussianities in multi-field inflationary models in Einstein gravity. We consider models governed by a Lagrangian which is a general function of the scalar fields and their first…

Astrophysics · Physics 2009-06-23 Xian Gao

We studied models of inflation with a preferred clock specifying the end of inflation and giving the curvature perturbations, coupled with another non-equivalent clock that at late times defines the same frame and do not contribute to the…

General Relativity and Quantum Cosmology · Physics 2013-10-18 Gustavo Joaquin Turiaci , Matias Zaldarriaga

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

In this paper we calculate additional contributions to that part of the non-Gaussianity of the curvature perturbation, which come from the three-point correlator of the field perturbations. We estimate this contribution in the following…

Astrophysics · Physics 2007-05-23 Ignacio Zaballa , Yeinzon Rodriguez , David H. Lyth