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Related papers: Non-Gaussianity from Features

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We carry out numerical investigations of the perturbations in Nflation models where the mass spectrum is generated by random matrix theory. The tensor-to-scalar ratio and non-gaussianity are already known to take the single-field values,…

Astrophysics · Physics 2008-12-18 Soo A Kim , Andrew R Liddle

In this note, we will introduce an action for warm inflation model with direct coupling between the pseudoscalar field and mass-less $SU(2)$ gauge fields. The potential of inflaton is protected against the thermal corrections in a thermal…

General Relativity and Quantum Cosmology · Physics 2019-08-21 Vahid. Kamali

Inflationary models with a scalar field nonminimally coupled both with the Ricci scalar and with the Gauss-Bonnet term are studied. We propose the way of generalization of inflationary scenarios with the Gauss-Bonnet term and a scalar field…

General Relativity and Quantum Cosmology · Physics 2021-07-21 Ekaterina O. Pozdeeva , Sergey Yu. Vernov

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

We study how the scalar power spectrum of single-scalar inflation depends functionally on models with features which have been proposed to explain anomalies in the data. We exploit a new formalism based on evolving the norm-squared of the…

General Relativity and Quantum Cosmology · Physics 2016-09-27 D. J. Brooker , N. C. Tsamis , R. P. Woodard

We study the evolution of non-Gaussianity in multiple-field inflationary models, focusing on three fundamental questions: (a) How is the sign and peak magnitude of the non-linearity parameter fNL related to generic features in the…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-07 Joseph Elliston , David Mulryne , David Seery , Reza Tavakol

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

Recently, it has been realized that the so-called G-inflation model inspired by supplementing a generalized covariant Galileon-like non-linear derivative self-interacting term to the standard kinetic term should be ruled out from…

General Relativity and Quantum Cosmology · Physics 2017-12-06 Maysam Motaharfar , Erfan Massaeli , Hamid Reza Sepangi

The inflationary paradigm has enjoyed phenomenological success, however, a compelling particle physics realization is still lacking. The key obstruction is that the requirement of a suitably flat scalar potential is sensitive to…

High Energy Physics - Phenomenology · Physics 2011-05-12 Neil Barnaby , Marco Peloso

We give a concise formula for the non-Gaussianity of the primordial curvature perturbation generated on super-horizon scales in multi-scalar inflation model without assuming slow-roll conditions. This is an extension of our previous work.…

Astrophysics · Physics 2013-01-11 Shuichiro Yokoyama , Teruaki Suyama , Takahiro Tanaka

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

Various inflationary scenarios can often be distinguished from one another by looking at the squeezed limit behavior of correlation functions. Therefore, it is useful to have a framework designed to study this limit in a more systematic and…

High Energy Physics - Theory · Physics 2016-08-19 Mehrdad Mirbabayi , Marko Simonović

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

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 study a nonminimal derivative inflationary model in the presence of the Gauss-Bonnet term. To have a complete treatment of the model, we consider a general form of the nonminimal derivative function and also the Gauss-Bonnet coupling…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-29 Kourosh Nozari , Narges Rashidi

We revisit inflation with non-canonical scalar fields by applying deformed-steepness exponential potentials. We show that the resulting scenario can lead to inflationary observables, and in particular to scalar spectral index and…

General Relativity and Quantum Cosmology · Physics 2021-08-24 Smaragda Lola , Andreas Lymperis , Emmanuel N. Saridakis

Inflationary attractors predict the spectral index and tensor-to-scalar ratio to take specific values that are consistent with Planck. An example is the universal attractor for models with a generalised non-minimal coupling, leading to…

High Energy Physics - Theory · Physics 2015-01-28 Benedict J. Broy , Diederik Roest , Alexander Westphal

We present accurate predictions of the correlation function of hotspots in the microwave background radiation for gaussian theories such as those predicted in most inflation models. The correlation function of peaks above a certain…

Astrophysics · Physics 2009-10-31 Alan F. Heavens , Ravi K. Sheth

In the literature there have been incompatible estimates for the amount of non-Gaussianity in hybrid inflation. In this note we point out the sources for the discrepancies and show that the results for the amount of non-Gaussianity in…

Astrophysics · Physics 2007-05-23 Antti Vaihkonen

Motivated by the prospect of testing inflation from precision cosmic microwave background observations, we present analytic results for scalar and tensor perturbations in single-field inflation models based on the application of uniform…

Astrophysics · Physics 2009-11-07 Salman Habib , Katrin Heitmann , Gerard Jungman , Carmen Molina-Paris