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Related papers: Initial Conditions for Non-Canonical Inflation

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We investigate the initial conditions of inflation in a Bianchi~I universe that is homogeneous but not isotropic. We use the Eisenhart lift to describe such a theory geometrically as geodesics on a field space manifold. We construct the…

General Relativity and Quantum Cosmology · Physics 2020-03-18 Kieran Finn

In this work, we explore the prospect of generalizing the constant-roll condition in canonical inflationary model to non-canonical models. To find a natural generalization, we focus on three manifestations of this condition and construct…

General Relativity and Quantum Cosmology · Physics 2024-05-07 S. Mohammad Ahmadi , Nahid Ahmadi , Mehdi Shokri

In the context of inflationary models with a pre-inflationary stage, in which the Einstein equations are obeyed, the weak energy condition is satisfied, and spacetime topology is trivial, we argue that homogeneity on super-Hubble scales…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Tanmay Vachaspati , Mark Trodden

While cosmological inflation can erase primordial inhomogeneities, it is possible that inflation may not begin in a significantly inhomogeneous universe. This issue is particularly pressing in multifield scenarios, where even the…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-25 Richard Easther , Layne C. Price , Javier Rasero

In this Thesis by publication, we cover both phenomenological and theoretical approaches to the study of inflation: from model-independent parametrizations to modifications of gravity. In a review style, we provide a short introduction to…

General Relativity and Quantum Cosmology · Physics 2019-06-25 Héctor Ramírez

A generalization of the canonical and non-canonical theory of inflation is introduced in which the kinetic energy term in action is written as non-local term. The inflationary universe within the framework of considering this non-locality…

General Relativity and Quantum Cosmology · Physics 2015-07-01 Haidar Sheikhahmadi , Soheyla Ghorbani , Khaled Saaidi

The behaviour of a non-canonical scalar field within an anisotropic Bianchi type I, spatially homogeneous, Universe in the framework of the intermediate inflation will be studied. It will be examined on the condition that both the…

General Physics · Physics 2019-08-19 Mahdeyeh Naderi , Ali Aghamohammadi , Abdollah Refaei , Haidar Sheikhahmadi

We consider how the swampland criteria might be applied to models in which scalar fields have nontrivial kinetic terms, particularly in the context of $P(\phi,X)$ theories, popularly used in approaches to inflation, to its alternatives, and…

High Energy Physics - Theory · Physics 2023-11-08 Adam R. Solomon , Mark Trodden

We study inflationary models where the kinetic sector of the theory has a non-linearly realised symmetry which is broken by the inflationary potential. We distinguish between kinetic symmetries which non-linearly realise an internal or…

High Energy Physics - Theory · Physics 2018-07-04 Remko Klein , Diederik Roest , David Stefanyszyn

We consider a general chaotic inflation model with non-canonical kinetic term, resulting in attractor solutions for the inflation of quadratic or other monomial type. In particular, the form of the kinetic term and the potential is fixed…

High Energy Physics - Phenomenology · Physics 2015-06-19 Hyun Min Lee

We investigate the effect of non-canonical kinetic terms on inflation in supergravity. We find that the biggest impact of such higher-derivative kinetic terms is due to the corrections to the potential that they induce via their effect on…

High Energy Physics - Theory · Physics 2015-06-18 Rhiannon Gwyn , Jean-Luc Lehners

Recently, a model of inflation using non-minimally coupled massive vector fields has been proposed. For a particular choice of non-minimal coupling parameter and for a flat FRW model, the model is reduced to the model of chaotic inflation…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Takeshi Chiba

Hybrid inflation faces two well-known problems: the blue spectrum of the non-supersymmetric version of the model and the fine-tuning of the initial conditions of the fields leading to sufficient inflation to account for the standard…

High Energy Physics - Phenomenology · Physics 2010-04-15 Sebastien Clesse , Jonathan Rocher

Inflation in cosmology is a specific stage preceding the Big Bang, aimed at solving both old background problems and new perturbation issues. Single-field inflation is a candidate to illustrate the picture of the initial universe, and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-21 Guanqiao Liu

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

We consider a noncommutative (NC) inflationary model with a homogeneous scalar field minimally coupled to gravity. The particular NC inflationary setting produces entirely new consequences. We first analyze the free field case and…

General Relativity and Quantum Cosmology · Physics 2018-05-01 S. M. M. Rasouli , N. Saba , M. Farhoudi , J. Marto , P. Moniz

Small-field inflation (SFI) is widely considered to be unnatural because an extreme fine-tuning of the initial condition is necessary for sufficiently large e-folding. In this paper, we show that the unnaturally-looking initial condition…

High Energy Physics - Phenomenology · Physics 2016-04-13 Satoshi Iso , Kazunori Kohri , Kengo Shimada

We develop a non-linear framework for describing long-wavelength perturbations in multiple-field inflation. The basic variables describing inhomogeneities are defined in a non-perturbative manner, are invariant under changes of time slicing…

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

In the phase space perspective, scalar field slow roll inflation is described by a heteroclinic orbit from a saddle type fixed point to a final attractive point. In many models the saddle point resides in the scalar field asymptotics, and…

General Relativity and Quantum Cosmology · Physics 2025-10-29 Laur Järv , Dmitri Kraiko

We study analytically and numerically the inflationary solutions for various type scalar potentials in the nonminimally coupled scalar field theory. The Hamilton-Jacobi equation is used to deal with nonlinear evolutions of inhomogeneous…

Astrophysics · Physics 2009-11-11 Seoktae Koh , Sang Pyo Kim , Doo Jong Song