Cosmological model with running vacuum energy and warm dark matter

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dc.contributor.advisor1Chapiro, Ilia
dc.contributor.advisor1IDhttps://orcid.org/0000-0001-6971-9409
dc.contributor.advisor1Latteshttp://lattes.cnpq.br/2644217574349073
dc.contributor.authorRuiz, Jhonny Andres Agudelo
dc.contributor.authorIDhttps://orcid.org/0000-0002-8918-5835
dc.contributor.authorLatteshttp://lattes.cnpq.br/3039931513015232
dc.contributor.referee1Fabris, Júlio César
dc.contributor.referee1IDhttps://orcid.org/000000018880107X
dc.contributor.referee1Latteshttp://lattes.cnpq.br/5193649615872035
dc.contributor.referee2Toribio, Alan Miguel Velasquez
dc.contributor.referee2IDhttps://orcid.org/0000-0002-2345-3999
dc.contributor.referee2Latteshttp://lattes.cnpq.br/1885284194756497
dc.contributor.referee3Piattella, Oliver Fabio
dc.contributor.referee3IDhttps://orcid.org/0000000345580574
dc.contributor.referee3Latteshttp://lattes.cnpq.br/5707156831919279
dc.contributor.referee4Rivera, Celia Del Carmen Escamilla
dc.contributor.referee4IDhttps://orcid.org/0000-0002-8929-250X
dc.contributor.referee4Latteshttp://lattes.cnpq.br/6858596344111096
dc.contributor.referee5Peter, Patrick
dc.contributor.referee5IDhttps://orcid.org/0000-0002-7136-8326
dc.contributor.referee5Latteshttp://lattes.cnpq.br/4674461245456989
dc.contributor.referee6Carballeira, Manuel Asorey
dc.contributor.referee6IDhttps://orcid.org/0000-0003-3669-6241
dc.date.accessioned2024-05-30T00:48:54Z
dc.date.available2024-05-30T00:48:54Z
dc.date.issued2021-01-28
dc.description.abstractThe core of the present thesis is the possibility of the change with the energy scale (running) of the cosmological constant. Theoretically, this running in the IR region is not ruled out. On the other hand, from the Quantum Field Theory (QFT) viewpoint, the energy released due to the variation of the cosmological constant in the late Universe cannot go to the matter sector. For this reason, the phenomenological bounds on such a running are not sufficiently restrictive. The situation can be different in the early Universe when the gravitational field was sufficiently strong to provide an efficient creation of particles from the vacuum. We develop a framework for systematically exploring this possibility. It is supposed that the running occurs in the epoch when the Dark Matter (DM) already decoupled and is expanding adiabatically, while the usual matter should be regarded approximately massless and can be abundantly created from vacuum due to the decay of vacuum energy. By using the handy model of Reduced Relativistic Gas (RRG) for describing the Warm Dark Matter (WDM), we consider the dynamics of both cosmic background and linear perturbations and evaluate the impact of the vacuum decay on the matter power spectrum and to the first CMB peak. Additionally, using the combined SNIa+BAO data, we find the best-fit values for the free parameters of the model. Additionally, it is known than the inclusion of spatial curvature can modify the evolution of matter perturbations and affect the Large Scale Structure (LSS) formation. We quantify the effects of the non-zero space curvature in terms of LSS formation for a cosmological model with a RCC and a WDM component. The evolution of density perturbations and the modified shape of its power spectrum are also reconstructed and analyzed in this context. Finally, it is analytically constructed the scalar field actions minimally and nonminimally coupled to gravity, which are equivalent to RRG (describing the WDM component) in the sense they produce the same cosmological solutions for the conformal factor of the metric. In particular, we construct the scalar theory which corresponds to the model of an ultra-relativistic ideal gas of spinless particles possessing conformal symmetry. The possibility of supplementing our scalar field model for WDM with dynamical dark energy in the form of a RCC is also considered.
dc.description.sponsorshipFundação Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
dc.formatText
dc.identifier.urihttp://repositorio.ufes.br/handle/10/14062
dc.languagepor
dc.publisherUniversidade Federal do Espírito Santo
dc.publisher.countryBR
dc.publisher.courseDoutorado em Astrofísica, Cosmologia e Gravitação
dc.publisher.departmentCentro de Ciências Exatas
dc.publisher.initialsUFES
dc.publisher.programPrograma de Pós-Graduação em Astrofísica, Cosmologia e Gravitação
dc.rightsopen access
dc.subjectConstante cosmológica variável
dc.subjectenergia de vácuo variável
dc.subjectmatéria escura morna
dc.subjectgás relativistico reduzido
dc.subjectteoria de campo escalar
dc.subject.br-rjbnsubject.br-rjbn
dc.subject.cnpqAstronomia
dc.titleCosmological model with running vacuum energy and warm dark matter
dc.typedoctoralThesis
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