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We develop a variant of the generalized slow roll approach for calculating the curvature power spectrum that is well-suited for order unity deviations in power caused by sharp features in the inflaton potential. As an example, we show that…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-07 Cora Dvorkin , Wayne Hu

We compute the 3-point correlation function for a general model of inflation driven by a single, minimally coupled scalar field. Our approach is based on the numerical evaluation of both the perturbation equations and the integrals which…

Astrophysics · Physics 2010-10-27 Xingang Chen , Richard Easther , Eugene A. Lim

We study the effects of a general type of features of the inflaton potential on the spectrum and bispectrum of primordial curvature perturbations. These features correspond to a discontinuity in the $n$-th order derivative of the potential…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-25 Alexander Gallego Cadavid

If cosmic inflation suffered tiny time-dependent deviations from the slow-roll regime, these would induce the existence of small scale-dependent features imprinted in the primordial spectra, with their shapes and sizes revealing information…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Sander Mooij , Gonzalo A. Palma , Grigoris Panotopoulos , Alex Soto

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

Motivated by the idea that inflation occurs at the GUT symmetry breaking scale, in this paper we construct a new class of large field inflaton potentials where the inflaton starts with a power law potential; after initial period of relative…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-24 Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

Features in the inflaton potential that are traversed in much less than an e-fold of the expansion can produce observably large non-Gaussianity. In these models first order corrections to the curvature mode function evolution induce effects…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-30 Peter Adshead , Wayne Hu

We develop methods to calculate the curvature power spectrum in models where features in the inflaton potential nonlinearly excite modes and generate high frequency features in the spectrum. The first nontrivial effect of excitations…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 V Miranda , Wayne Hu , Chen He , Hayato Motohashi

We develop a fast technique based on the generalized slow roll (GSR) approach for computing the curvature bispectrum of inflationary models with features. We show that all triangle configurations can be expressed in terms of three simple…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-02 Peter Adshead , Wayne Hu , Cora Dvorkin , Hiranya V. Peiris

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

We update the constraints on possible features in the primordial inflationary density perturbation spectrum by using the latest data from the WMAP7 and ACT Cosmic Microwave Background experiments. The inclusion of new data significantly…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Micol Benetti , Massimiliano Lattanzi , Erminia Calabrese , Alessandro Melchiorri

We present primordial non-Gaussianity predictions from a new high-precision code for simulating axion-U(1) inflation on a discrete lattice. We measure the primordial scalar curvature power spectrum and bispectrum from our simulations,…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-26 Drew Jamieson , Angelo Caravano , Eiichiro Komatsu

Non-linear interactions during inflation generate non-Gaussianities in the distribution of primordial curvature. In many theories, the physics is scale-invariant, such that the induced three-point function depends solely on a dimensionless…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-27 Oliver H. E. Philcox

We study the hybrid inflationary potential in a regime where the defect field is light, and more than 60 e-folds of accelerated expansion occur after the symmetry breaking transition. Using analytic and numerical techniques, we then…

High Energy Physics - Theory · Physics 2013-05-29 David Mulryne , Stefano Orani , Arttu Rajantie

Combining Planck CMB temperature [1] and BICEP2 B-mode polarization data [2,3] we show qualitatively that, assuming inflationary consistency relation, the power-law form of the scalar primordial spectrum is ruled out at more than $3\sigma$…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-17 Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

In this work, we analyze a power-law inflationary potential enhanced with a step that can introduce features in the primordial power spectrum. We focus on the computation of the Spectral Distortions (SD) induced by these features obtained…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-27 Jorge Mastache , Wilson Barrera , Raúl Henríquez-Ortiz

Many models of inflation predict oscillatory features in the bispectrum of primordial fluctuations. Since it has been shown that primordial non-Gaussianity can lead to a scale-dependent halo bias, we investigate the effect of oscillations…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-20 Francis-Yan Cyr-Racine , Fabian Schmidt

We study slow-roll inflation with a Gauss-Bonnet term that is coupled to an inflaton field nonminimally. We investigate the inflationary solutions for a specific type of the nonminimal coupling to the Gauss-Bonnet term and inflaton…

General Relativity and Quantum Cosmology · Physics 2014-10-08 Seoktae Koh , Bum-Hoon Lee , Wonwoo Lee , Gansukh Tumurtushaa

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

A sudden small change in the second derivative of the inflaton potential can result in a universal local feature in the spectrum of primordial perturbations generated during inflation. The exact solution describing this feature \cite{minu}…

Astrophysics · Physics 2009-07-22 Minu Joy , Arman Shafieloo , Varun Sahni , Alexei A. Starobinsky
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