Supernova constraints on decaying vacuum cosmology
Autor(a) principal: | |
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Data de Publicação: | 2006 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFBA |
Texto Completo: | http://repositorio.ufba.br/ri/handle/ri/13744 |
Resumo: | There is mounting observational evidence that the expansion of our Universe is undergoing a late-time acceleration. Among many proposals to describe this phenomenon, the cosmological constant (Λ) seems to be the simplest and the most natural explanation. However, despite its observational successes, such a possibility exacerbates the well known Λ problem, requiring a natural explanation for its small, but nonzero, value. In this paper we consider a cosmological scenario driven by a varying cosmological term, in which the vacuum energy density decays linearly with the Hubble parameter, Λ∝H. We show that this Λ(t)CDM model is indistinguishable from the standard one (ΛCDM) in that the early radiation phase is followed by a long dust-dominated era, and only recently the varying Λ term becomes dominant, accelerating the cosmic expansion. In order to test the viability of this scenario, we have used the most recent type Ia supernova data, i.e., the High-Z SN Search Team and the Supernova Legacy Survey (SNLS) Collaboration data. In particular, for the SNLS sample we have found 0.27≤Ωm≤0.37 and 0.68≤H0≤0.72 (at 2σ), which is in good agreement with the currently accepted estimates for these parameters. |
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Silva, Saulo Carneiro de SouzaPigozzo, Cássio Bruno MagalhãesBorges, Humberto de AlmeidaAlcaniz, Jailson Souza de2013-11-19T19:53:13Z2013-11-19T19:53:13Z20061550-7998http://repositorio.ufba.br/ri/handle/ri/13744v. 74, n. 2There is mounting observational evidence that the expansion of our Universe is undergoing a late-time acceleration. Among many proposals to describe this phenomenon, the cosmological constant (Λ) seems to be the simplest and the most natural explanation. However, despite its observational successes, such a possibility exacerbates the well known Λ problem, requiring a natural explanation for its small, but nonzero, value. In this paper we consider a cosmological scenario driven by a varying cosmological term, in which the vacuum energy density decays linearly with the Hubble parameter, Λ∝H. We show that this Λ(t)CDM model is indistinguishable from the standard one (ΛCDM) in that the early radiation phase is followed by a long dust-dominated era, and only recently the varying Λ term becomes dominant, accelerating the cosmic expansion. In order to test the viability of this scenario, we have used the most recent type Ia supernova data, i.e., the High-Z SN Search Team and the Supernova Legacy Survey (SNLS) Collaboration data. In particular, for the SNLS sample we have found 0.27≤Ωm≤0.37 and 0.68≤H0≤0.72 (at 2σ), which is in good agreement with the currently accepted estimates for these parameters.Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2013-08-01T17:39:12Z No. of bitstreams: 1 e023532.pdf: 219367 bytes, checksum: 58c60b711e05a36515133445d398a5a1 (MD5)Approved for entry into archive by Rodrigo Meirelles (rodrigomei@ufba.br) on 2013-11-19T19:53:12Z (GMT) No. of bitstreams: 1 e023532.pdf: 219367 bytes, checksum: 58c60b711e05a36515133445d398a5a1 (MD5)Made available in DSpace on 2013-11-19T19:53:13Z (GMT). No. of bitstreams: 1 e023532.pdf: 219367 bytes, checksum: 58c60b711e05a36515133445d398a5a1 (MD5) Previous issue date: 2006http://dx.doi.org/10.1103/PhysRevD.74.023532reponame:Repositório Institucional da UFBAinstname:Universidade Federal da Bahia (UFBA)instacron:UFBASupernova constraints on decaying vacuum cosmologyPhysical Review Dinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleBrasilinfo:eu-repo/semantics/openAccessengORIGINALe023532.pdfe023532.pdfapplication/pdf219367https://repositorio.ufba.br/bitstream/ri/13744/1/e023532.pdf58c60b711e05a36515133445d398a5a1MD51LICENSElicense.txtlicense.txttext/plain1762https://repositorio.ufba.br/bitstream/ri/13744/2/license.txt1b89a9a0548218172d7c829f87a0eab9MD52TEXTe023532.pdf.txte023532.pdf.txtExtracted texttext/plain28271https://repositorio.ufba.br/bitstream/ri/13744/3/e023532.pdf.txt05a1ccb415a1d8014fef0421be8f3481MD53ri/137442022-03-10 14:08:24.822oai:repositorio.ufba.br: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Repositório InstitucionalPUBhttp://192.188.11.11:8080/oai/requestopendoar:19322022-03-10T17:08:24Repositório Institucional da UFBA - Universidade Federal da Bahia (UFBA)false |
dc.title.pt_BR.fl_str_mv |
Supernova constraints on decaying vacuum cosmology |
dc.title.alternative.pt_BR.fl_str_mv |
Physical Review D |
title |
Supernova constraints on decaying vacuum cosmology |
spellingShingle |
Supernova constraints on decaying vacuum cosmology Silva, Saulo Carneiro de Souza |
title_short |
Supernova constraints on decaying vacuum cosmology |
title_full |
Supernova constraints on decaying vacuum cosmology |
title_fullStr |
Supernova constraints on decaying vacuum cosmology |
title_full_unstemmed |
Supernova constraints on decaying vacuum cosmology |
title_sort |
Supernova constraints on decaying vacuum cosmology |
author |
Silva, Saulo Carneiro de Souza |
author_facet |
Silva, Saulo Carneiro de Souza Pigozzo, Cássio Bruno Magalhães Borges, Humberto de Almeida Alcaniz, Jailson Souza de |
author_role |
author |
author2 |
Pigozzo, Cássio Bruno Magalhães Borges, Humberto de Almeida Alcaniz, Jailson Souza de |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Silva, Saulo Carneiro de Souza Pigozzo, Cássio Bruno Magalhães Borges, Humberto de Almeida Alcaniz, Jailson Souza de |
description |
There is mounting observational evidence that the expansion of our Universe is undergoing a late-time acceleration. Among many proposals to describe this phenomenon, the cosmological constant (Λ) seems to be the simplest and the most natural explanation. However, despite its observational successes, such a possibility exacerbates the well known Λ problem, requiring a natural explanation for its small, but nonzero, value. In this paper we consider a cosmological scenario driven by a varying cosmological term, in which the vacuum energy density decays linearly with the Hubble parameter, Λ∝H. We show that this Λ(t)CDM model is indistinguishable from the standard one (ΛCDM) in that the early radiation phase is followed by a long dust-dominated era, and only recently the varying Λ term becomes dominant, accelerating the cosmic expansion. In order to test the viability of this scenario, we have used the most recent type Ia supernova data, i.e., the High-Z SN Search Team and the Supernova Legacy Survey (SNLS) Collaboration data. In particular, for the SNLS sample we have found 0.27≤Ωm≤0.37 and 0.68≤H0≤0.72 (at 2σ), which is in good agreement with the currently accepted estimates for these parameters. |
publishDate |
2006 |
dc.date.issued.fl_str_mv |
2006 |
dc.date.accessioned.fl_str_mv |
2013-11-19T19:53:13Z |
dc.date.available.fl_str_mv |
2013-11-19T19:53:13Z |
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://repositorio.ufba.br/ri/handle/ri/13744 |
dc.identifier.issn.none.fl_str_mv |
1550-7998 |
dc.identifier.number.pt_BR.fl_str_mv |
v. 74, n. 2 |
identifier_str_mv |
1550-7998 v. 74, n. 2 |
url |
http://repositorio.ufba.br/ri/handle/ri/13744 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
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openAccess |
dc.publisher.country.fl_str_mv |
Brasil |
dc.source.pt_BR.fl_str_mv |
http://dx.doi.org/10.1103/PhysRevD.74.023532 |
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