The spherical collapse model in time varying vacuum cosmologies
We investigate the virialization of cosmic structures in the framework of flat Friedmann-Lemaitre-Robertson-Walker cosmological models, in which the vacuum energy density evolves with time. In particular, our analysis focuses on the study of spherical matter perturbations, as they decouple from the...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2010 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/131710 |
| Acceso en línea: | https://hdl.handle.net/2445/131710 |
| Access Level: | acceso abierto |
| Palabra clave: | Col·lapse gravitacional Cosmologia Gravitational collapse Cosmology |
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The spherical collapse model in time varying vacuum cosmologiesBasilakos, SpyrosPlionis, ManolisSolà Peracaula, JoanCol·lapse gravitacionalCosmologiaGravitational collapseCosmologyWe investigate the virialization of cosmic structures in the framework of flat Friedmann-Lemaitre-Robertson-Walker cosmological models, in which the vacuum energy density evolves with time. In particular, our analysis focuses on the study of spherical matter perturbations, as they decouple from the background expansion, "turn around," and finally collapse. We generalize the spherical collapse model in the case when the vacuum energy is a running function of the Hubble rate, Λ = Λ ( H ) . A particularly well-motivated model of this type is the so-called quantum field vacuum, in which Λ ( H ) is a quadratic function, Λ ( H ) = n 0 + n 2 H 2 , with n 0 ≠ 0 . This model was previously studied by our team using the latest high quality cosmological data to constrain its free parameters, as well as the predicted cluster formation rate. It turns out that the corresponding Hubble expansion history resembles that of the traditional Λ CDM cosmology. We use this Λ ( t ) CDM framework to illustrate the fact that the properties of the spherical collapse model (virial density, collapse factor, etc.) depend on the choice of the considered vacuum energy (homogeneous or clustered). In particular, if the distribution of the vacuum energy is clustered, then, under specific conditions, we can produce more concentrated structures with respect to the homogeneous vacuum energy case.American Physical Society2010info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/131710Articles publicats en revistes (Física Quàntica i Astrofísica)reponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglésReproducció del document publicat a: https://doi.org/10.1103/PhysRevD.82.083512Physical Review D, 2010, vol. D82, num. 8, p. 113005https://doi.org/10.1103/PhysRevD.82.083512(c) American Physical Society, 2010info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/1317102026-05-27T06:46:51Z |
| dc.title.none.fl_str_mv |
The spherical collapse model in time varying vacuum cosmologies |
| title |
The spherical collapse model in time varying vacuum cosmologies |
| spellingShingle |
The spherical collapse model in time varying vacuum cosmologies Basilakos, Spyros Col·lapse gravitacional Cosmologia Gravitational collapse Cosmology |
| title_short |
The spherical collapse model in time varying vacuum cosmologies |
| title_full |
The spherical collapse model in time varying vacuum cosmologies |
| title_fullStr |
The spherical collapse model in time varying vacuum cosmologies |
| title_full_unstemmed |
The spherical collapse model in time varying vacuum cosmologies |
| title_sort |
The spherical collapse model in time varying vacuum cosmologies |
| dc.creator.none.fl_str_mv |
Basilakos, Spyros Plionis, Manolis Solà Peracaula, Joan |
| author |
Basilakos, Spyros |
| author_facet |
Basilakos, Spyros Plionis, Manolis Solà Peracaula, Joan |
| author_role |
author |
| author2 |
Plionis, Manolis Solà Peracaula, Joan |
| author2_role |
author author |
| dc.subject.none.fl_str_mv |
Col·lapse gravitacional Cosmologia Gravitational collapse Cosmology |
| topic |
Col·lapse gravitacional Cosmologia Gravitational collapse Cosmology |
| description |
We investigate the virialization of cosmic structures in the framework of flat Friedmann-Lemaitre-Robertson-Walker cosmological models, in which the vacuum energy density evolves with time. In particular, our analysis focuses on the study of spherical matter perturbations, as they decouple from the background expansion, "turn around," and finally collapse. We generalize the spherical collapse model in the case when the vacuum energy is a running function of the Hubble rate, Λ = Λ ( H ) . A particularly well-motivated model of this type is the so-called quantum field vacuum, in which Λ ( H ) is a quadratic function, Λ ( H ) = n 0 + n 2 H 2 , with n 0 ≠ 0 . This model was previously studied by our team using the latest high quality cosmological data to constrain its free parameters, as well as the predicted cluster formation rate. It turns out that the corresponding Hubble expansion history resembles that of the traditional Λ CDM cosmology. We use this Λ ( t ) CDM framework to illustrate the fact that the properties of the spherical collapse model (virial density, collapse factor, etc.) depend on the choice of the considered vacuum energy (homogeneous or clustered). In particular, if the distribution of the vacuum energy is clustered, then, under specific conditions, we can produce more concentrated structures with respect to the homogeneous vacuum energy case. |
| publishDate |
2010 |
| dc.date.none.fl_str_mv |
2010 |
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info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
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article |
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publishedVersion |
| dc.identifier.none.fl_str_mv |
https://hdl.handle.net/2445/131710 |
| url |
https://hdl.handle.net/2445/131710 |
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Inglés |
| language_invalid_str_mv |
Inglés |
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Reproducció del document publicat a: https://doi.org/10.1103/PhysRevD.82.083512 Physical Review D, 2010, vol. D82, num. 8, p. 113005 https://doi.org/10.1103/PhysRevD.82.083512 |
| dc.rights.none.fl_str_mv |
(c) American Physical Society, 2010 info:eu-repo/semantics/openAccess |
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(c) American Physical Society, 2010 |
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openAccess |
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application/pdf |
| dc.publisher.none.fl_str_mv |
American Physical Society |
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American Physical Society |
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Articles publicats en revistes (Física Quàntica i Astrofísica) reponame:Dipòsit Digital de la UB instname:Universidad de Barcelona |
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Universidad de Barcelona |
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Dipòsit Digital de la UB |
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Dipòsit Digital de la UB |
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15.301603 |