Cosmological axial gravitational waves in the f(R) Starobinsky model
Autor(a) principal: | |
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Data de Publicação: | 2021 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1140/epjp/s13360-021-01413-z http://hdl.handle.net/11449/206230 |
Resumo: | We investigate the propagation of cosmological axial (or odd parity) gravitational waves (GWs) in the framework of the f(R) gravity with f(R) = R+ λR2, the Starobinsky model. The metric tensor and the energy–momentum tensor of matter are perturbed by using the Regge–Wheeler axial perturbations framework. We solve the coupled system of differential equations of the perturbation parameters for two cosmological eras in which simply analytical solutions can be found, namely the radiation-dominated epoch and the de Sitter stage. In the former case, the Starobinsky model predicts exactly the same result of the General Relativity theory. On the other hand, remembering that in the Starobinsky inflation, the Universe starts within a metastable de Sitter state, we find the evolution of the axial GWs for this early epoch. In this sense, our results should be interpreted as the initial conditions for axial GWs in the Starobinsky model. We show how the initial evolution of axial GWs is affected by the presence of the higher-order curvature term and how it depends on the model parameter λ. Certainly, such an effect could leave an imprint on the spectrum of axial GWs at the end of the Starobinsky inflation, but this is a subject of further investigations. |
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Repositório Institucional da UNESP |
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Cosmological axial gravitational waves in the f(R) Starobinsky modelWe investigate the propagation of cosmological axial (or odd parity) gravitational waves (GWs) in the framework of the f(R) gravity with f(R) = R+ λR2, the Starobinsky model. The metric tensor and the energy–momentum tensor of matter are perturbed by using the Regge–Wheeler axial perturbations framework. We solve the coupled system of differential equations of the perturbation parameters for two cosmological eras in which simply analytical solutions can be found, namely the radiation-dominated epoch and the de Sitter stage. In the former case, the Starobinsky model predicts exactly the same result of the General Relativity theory. On the other hand, remembering that in the Starobinsky inflation, the Universe starts within a metastable de Sitter state, we find the evolution of the axial GWs for this early epoch. In this sense, our results should be interpreted as the initial conditions for axial GWs in the Starobinsky model. We show how the initial evolution of axial GWs is affected by the presence of the higher-order curvature term and how it depends on the model parameter λ. Certainly, such an effect could leave an imprint on the spectrum of axial GWs at the end of the Starobinsky inflation, but this is a subject of further investigations.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Department of Mathematics Virtual University of Pakistan, 54-Lawrence RoadUniversidade Estadual Paulista (UNESP) Instituto de Ciência e TecnologiaUniversidade Estadual Paulista (UNESP) Instituto de Ciência e TecnologiaFAPESP: 2013/26258-4Virtual University of PakistanUniversidade Estadual Paulista (Unesp)Siddiqa, AishaMehwish, Syeda Z. B.Alves, Márcio E. S. [UNESP]2021-06-25T10:28:40Z2021-06-25T10:28:40Z2021-04-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1140/epjp/s13360-021-01413-zEuropean Physical Journal Plus, v. 136, n. 4, 2021.2190-5444http://hdl.handle.net/11449/20623010.1140/epjp/s13360-021-01413-z2-s2.0-85104664306Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengEuropean Physical Journal Plusinfo:eu-repo/semantics/openAccess2021-10-23T00:57:08Zoai:repositorio.unesp.br:11449/206230Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T17:56:00.029642Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Cosmological axial gravitational waves in the f(R) Starobinsky model |
title |
Cosmological axial gravitational waves in the f(R) Starobinsky model |
spellingShingle |
Cosmological axial gravitational waves in the f(R) Starobinsky model Siddiqa, Aisha |
title_short |
Cosmological axial gravitational waves in the f(R) Starobinsky model |
title_full |
Cosmological axial gravitational waves in the f(R) Starobinsky model |
title_fullStr |
Cosmological axial gravitational waves in the f(R) Starobinsky model |
title_full_unstemmed |
Cosmological axial gravitational waves in the f(R) Starobinsky model |
title_sort |
Cosmological axial gravitational waves in the f(R) Starobinsky model |
author |
Siddiqa, Aisha |
author_facet |
Siddiqa, Aisha Mehwish, Syeda Z. B. Alves, Márcio E. S. [UNESP] |
author_role |
author |
author2 |
Mehwish, Syeda Z. B. Alves, Márcio E. S. [UNESP] |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
Virtual University of Pakistan Universidade Estadual Paulista (Unesp) |
dc.contributor.author.fl_str_mv |
Siddiqa, Aisha Mehwish, Syeda Z. B. Alves, Márcio E. S. [UNESP] |
description |
We investigate the propagation of cosmological axial (or odd parity) gravitational waves (GWs) in the framework of the f(R) gravity with f(R) = R+ λR2, the Starobinsky model. The metric tensor and the energy–momentum tensor of matter are perturbed by using the Regge–Wheeler axial perturbations framework. We solve the coupled system of differential equations of the perturbation parameters for two cosmological eras in which simply analytical solutions can be found, namely the radiation-dominated epoch and the de Sitter stage. In the former case, the Starobinsky model predicts exactly the same result of the General Relativity theory. On the other hand, remembering that in the Starobinsky inflation, the Universe starts within a metastable de Sitter state, we find the evolution of the axial GWs for this early epoch. In this sense, our results should be interpreted as the initial conditions for axial GWs in the Starobinsky model. We show how the initial evolution of axial GWs is affected by the presence of the higher-order curvature term and how it depends on the model parameter λ. Certainly, such an effect could leave an imprint on the spectrum of axial GWs at the end of the Starobinsky inflation, but this is a subject of further investigations. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-06-25T10:28:40Z 2021-06-25T10:28:40Z 2021-04-01 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1140/epjp/s13360-021-01413-z European Physical Journal Plus, v. 136, n. 4, 2021. 2190-5444 http://hdl.handle.net/11449/206230 10.1140/epjp/s13360-021-01413-z 2-s2.0-85104664306 |
url |
http://dx.doi.org/10.1140/epjp/s13360-021-01413-z http://hdl.handle.net/11449/206230 |
identifier_str_mv |
European Physical Journal Plus, v. 136, n. 4, 2021. 2190-5444 10.1140/epjp/s13360-021-01413-z 2-s2.0-85104664306 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
European Physical Journal Plus |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1808128876720685056 |