A Study of the Early Cosmic Dynamics in a Multifield Model of Inflation and Curvature Perturbations

In this work, we study the cosmological dynamics of the early universe by employing a small field potential in the context of multifield inflation. By investigating analytically the cosmological observables, such as the number of e-folds N, potential slow-roll parameters ϵV, ηV, and spectral index n...

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Main Authors: Muhammad Zahid Mughal, Feroz Khan, Fuad A. Awwad, Emad A. A. Ismail
Format: Article
Language:English
Published: Wiley 2024-01-01
Series:Advances in Astronomy
Online Access:http://dx.doi.org/10.1155/2024/8446071
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author Muhammad Zahid Mughal
Feroz Khan
Fuad A. Awwad
Emad A. A. Ismail
author_facet Muhammad Zahid Mughal
Feroz Khan
Fuad A. Awwad
Emad A. A. Ismail
author_sort Muhammad Zahid Mughal
collection DOAJ
description In this work, we study the cosmological dynamics of the early universe by employing a small field potential in the context of multifield inflation. By investigating analytically the cosmological observables, such as the number of e-folds N, potential slow-roll parameters ϵV, ηV, and spectral index ns which carry significant information, we show that they impact the inflationary universe considerably. The tensor-to-scalar ratio concerning the curvature perturbation is worked out for the potential under consideration which is another significant observable and comes out to be nonnegative. In multifield models of inflation, both types of curvature and isocurvature perturbations exist, while, in the present work, during the slow-roll, isocurvature perturbations are suppressed and therefore can be neglected. The surviving perturbations which are due to the curvature only can be tackled suitably by a mechanism developed by Sasaki and Stewart known as Sasaki–Stewart formalism. The effect of augmenting the number of e-folds on the power spectrum through the spectral index and its impact on the observable parameters of the slow-roll inflationary phase is observed by carrying out the analysis. It is observed analytically that the spectrum of multifield inflation is effectively different than its corresponding single-field inflation. The field values and their masses affect the results profoundly at the time of horizon-crossing.
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spelling doaj-art-c0dc9ed625cd4d6ebe11da5ead1c9eba2025-08-20T02:19:23ZengWileyAdvances in Astronomy1687-79772024-01-01202410.1155/2024/8446071A Study of the Early Cosmic Dynamics in a Multifield Model of Inflation and Curvature PerturbationsMuhammad Zahid Mughal0Feroz Khan1Fuad A. Awwad2Emad A. A. Ismail3Department of MathematicsDepartment of MathematicsDepartment of Quantitative AnalysisDepartment of Quantitative AnalysisIn this work, we study the cosmological dynamics of the early universe by employing a small field potential in the context of multifield inflation. By investigating analytically the cosmological observables, such as the number of e-folds N, potential slow-roll parameters ϵV, ηV, and spectral index ns which carry significant information, we show that they impact the inflationary universe considerably. The tensor-to-scalar ratio concerning the curvature perturbation is worked out for the potential under consideration which is another significant observable and comes out to be nonnegative. In multifield models of inflation, both types of curvature and isocurvature perturbations exist, while, in the present work, during the slow-roll, isocurvature perturbations are suppressed and therefore can be neglected. The surviving perturbations which are due to the curvature only can be tackled suitably by a mechanism developed by Sasaki and Stewart known as Sasaki–Stewart formalism. The effect of augmenting the number of e-folds on the power spectrum through the spectral index and its impact on the observable parameters of the slow-roll inflationary phase is observed by carrying out the analysis. It is observed analytically that the spectrum of multifield inflation is effectively different than its corresponding single-field inflation. The field values and their masses affect the results profoundly at the time of horizon-crossing.http://dx.doi.org/10.1155/2024/8446071
spellingShingle Muhammad Zahid Mughal
Feroz Khan
Fuad A. Awwad
Emad A. A. Ismail
A Study of the Early Cosmic Dynamics in a Multifield Model of Inflation and Curvature Perturbations
Advances in Astronomy
title A Study of the Early Cosmic Dynamics in a Multifield Model of Inflation and Curvature Perturbations
title_full A Study of the Early Cosmic Dynamics in a Multifield Model of Inflation and Curvature Perturbations
title_fullStr A Study of the Early Cosmic Dynamics in a Multifield Model of Inflation and Curvature Perturbations
title_full_unstemmed A Study of the Early Cosmic Dynamics in a Multifield Model of Inflation and Curvature Perturbations
title_short A Study of the Early Cosmic Dynamics in a Multifield Model of Inflation and Curvature Perturbations
title_sort study of the early cosmic dynamics in a multifield model of inflation and curvature perturbations
url http://dx.doi.org/10.1155/2024/8446071
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