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Related papers: Slow roll in simple non-canonical inflation

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Slow-roll inflationary scenario is considered in non-canonical scalar field model supposing a power-law function for kinetic term, and using two formalisms. In the first approach, the potential is considered as a power-law function, that is…

General Relativity and Quantum Cosmology · Physics 2017-08-15 Kh. Saaidi , A. Mohammadi , T. Golanbari

We consider non-canonical generalizations of two classes of simple single-field inflation models. First, we study the non-canonical version of "ultra-slow roll" inflation, which is a class of inflation models for which quantum modes do not…

Astrophysics · Physics 2009-11-13 Konstantinos Tzirakis , William H. Kinney

We examine the dynamics of inflation driven by multiple, interacting scalar fields and derive a multi field version of the Hubble slow roll expansion. We show that the properties of this expansion naturally generalize those of the single…

Astrophysics · Physics 2013-05-29 Richard Easther , John T Giblin

We formalize the Hubble slow-roll formalism for inflationary dynamics in Randall-Sundrum Type II braneworld cosmologies, defining Hubble slow-roll parameters which can be used along with the Hamilton-Jacobi formalism. Focussing on the…

Astrophysics · Physics 2009-11-10 Erandy Ramirez , Andrew R. Liddle

We present a new approach to quintessential inflation, in which both dark energy and inflation are explained by the evolution of a single scalar field. We start from a simple scalar potential with both oscillatory and exponential behavior.…

Astrophysics · Physics 2009-11-10 Gabriela Barenboim , Joseph Lykken

We show that the generalized slow-roll approach for calculating the power spectrum where the inflationary slow roll parameters are neither small nor slowly varying can be readily extended to models with non-canonical kinetic terms in the…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-09 Wayne Hu

Stochastic inflation, together with the $\Delta N$ formalism, provides a powerful tool for estimating the large-scale behaviour of primordial fluctuations. In this work, we develop a numerical code to capture the non-perturbative statistics…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-10 Devanshu Sharma

In the slow-roll inflationary scenario, the amplitude of the curvature perturbations approaches a constant value soon after the modes leave the Hubble radius. However, relatively recently, it was shown that the amplitude of the curvature…

Astrophysics · Physics 2008-11-26 Rajeev Kumar Jain , Pravabati Chingangbam , L. Sriramkumar

The conventional slow-roll approximation is broken in the so-called "ultra slow-roll" models of inflation, for which the inflaton potential is exactly (or extremely) flat. The interesting nature of (canonical) ultra slow-roll inflation is…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-18 Shin'ichi Hirano , Tsutomu Kobayashi , Shuichiro Yokoyama

Nongaussian statistics are a powerful discriminant between inflationary models, particularly those with noncanonical kinetic terms. Focusing on theories where the Lagrangian is an arbitrary Lorentz-invariant function of a scalar field and…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Clare Burrage , Raquel H. Ribeiro , David Seery

We study non-linear contributions to the power spectrum of the curvature perturbation on super-horizon scales, produced during slow-roll inflation driven by a canonical single scalar field. We find that on large scales the linear power…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Jinn-Ouk Gong , Hyerim Noh , Jai-chan Hwang

We look for potential observational degeneracies between canonical and non-canonical models of inflation of a single field $\phi$. Non-canonical inflationary models are characterized by higher than linear powers of the standard kinetic term…

High Energy Physics - Theory · Physics 2015-06-12 Rhiannon Gwyn , Markus Rummel , Alexander Westphal

We present a complete numerical treatment of inflationary dynamics under the influence of stochastic corrections from sub-Hubble modes. We discuss how to exactly model the stochastic noise terms arising from the sub-Hubble quantum modes…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-02 Aritra De , Rafid Mahbub

We argue that in models of inflation with two scalar fields and non-canonical kinetic terms there is a possibility of obtaining a red tilt of the power spectrum of curvature perturbations from noncanonicality-induced interactions between…

High Energy Physics - Theory · Physics 2015-03-17 Sera Cremonini , Zygmunt Lalak , Krzysztof Turzynski

As is well known, the non-Gaussianity parameter $f_{_{\rm NL}}$, which is often used to characterize the amplitude of the scalar bi-spectrum, can be expressed completely in terms of the scalar spectral index $n_{\rm s}$ in the squeezed…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 V. Sreenath , Dhiraj Kumar Hazra , L. Sriramkumar

We study the slow-roll regime of two field inflation, in which the two fields are also coupled through their kinetic terms. Such Lagrangians are motivated by particle physics and by scalar-tensor theories studied in the Einstein frame. We…

Astrophysics · Physics 2009-11-11 Fabrizio Di Marco , Fabio Finelli

The scenario of constant-roll inflation is studied where the inflaton is a scalar field with modified kinetic term, known as non-canonical scalar field. This modification leads to some changes in the slow-roll parameters, and also by taking…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-23 Abolhassan Mohammadi , Khaled Saaidi , Haidar Sheikhahmadi

Motivated by trans-Planckian issues in inflation, we determine the Hilbert space and amplitudes of quantum perturbations in the general low-energy effective theory of (multi-)field inflation without relying on the sub-horizon limit. The…

High Energy Physics - Theory · Physics 2026-05-29 Andrea Ambrosi de Magistris , Alberto Salvio

A study of the slow-roll inflation for an exponential potential in the frame of the scalar-tensor theory is performed, where non-minimal kinetic coupling to curvature and non-minimal coupling of the scalar field to the Gauss-Bonnet…

High Energy Physics - Theory · Physics 2019-09-24 L. N. Granda , D. F. Jimenez

One possibility for identifying the inflaton in the framework of string theory is that it is a $D$-brane modulus. This option involves a specific, non-canonical form of the kinetic energy -- the Dirac-Born-Infeld action. This note…

High Energy Physics - Theory · Physics 2010-10-27 Michal Spalinski
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