Modelos Simples de Lemaitre - Tolman - Bondi (LTB)
Autor(a) principal: | |
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Data de Publicação: | 2015 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da Universidade Federal do Espírito Santo (riUfes) |
Texto Completo: | http://repositorio.ufes.br/handle/10/7459 |
Resumo: | The current standard model of cosmology, the ?CDM model (?-Cold Dark Matter), is on the homogeneous solutions of Friedmann-Lemaître-Robertson-Walker (FLRW) of Einstein’s equations. The characteristics of the Cosmic Microwave Background (CMB) and structure formation on large scales are studied through the theory of cosmological perturbations in homogeneous and isotropic background. However, in the last fifteen years, "simple" inhomogeneous cosmological models that are generalizations of FLRW cosmological model gained interest in astrophysics community and have been used to study cosmological phenomena. Some authors have shown that these inhomogeneous models with spherical symmetry and dust source can play a good fit for the data type Ia supernovae (SNIa) and the position of the first peak of the CMB. These models suggest that the apparent accelerated expansion of the universe is not caused by the repulsive gravity due to dark energy, but is rather a result of inhomogeneities in the distribution of matter. In this dissertation, inhomogeneous models of the Universe are investigated on the basis of Lemaître-Tolman-Bondi (LTB) metric, which represents a spherical symmetry solution to dust. Two particular models are studied: the parabolic evolution with inhomogeneous Big Bang’s time and the of hyperbolic evolution with weak curvature and constant Big Bang’s time. The properties of each of these models are investigated in detail, as analitically as possible. Both models are compared with astrophysical observations of the sample Union2.1 SNIa. It is conclude that these models could be a starting point to develop more realistic models. Thus LTB solution is capable to explain the observed relationship between distance luminosity and redshift of supernovae without the requirement of dark energy when the inhomogeneity is either the form of an empty or there is a hill centered on the observer; with the further assumption that the outside Universe, in both cases, is approxinately described by the Einstein-de sitter homogeneous model. |
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Isidro, Eddy Giusepe ChirinosFalciano, Felipe TovarMarra, ValerioPiattella, Oliver Fabio2018-08-01T22:29:42Z2018-08-012018-08-01T22:29:42Z2015-05-07The current standard model of cosmology, the ?CDM model (?-Cold Dark Matter), is on the homogeneous solutions of Friedmann-Lemaître-Robertson-Walker (FLRW) of Einstein’s equations. The characteristics of the Cosmic Microwave Background (CMB) and structure formation on large scales are studied through the theory of cosmological perturbations in homogeneous and isotropic background. However, in the last fifteen years, "simple" inhomogeneous cosmological models that are generalizations of FLRW cosmological model gained interest in astrophysics community and have been used to study cosmological phenomena. Some authors have shown that these inhomogeneous models with spherical symmetry and dust source can play a good fit for the data type Ia supernovae (SNIa) and the position of the first peak of the CMB. These models suggest that the apparent accelerated expansion of the universe is not caused by the repulsive gravity due to dark energy, but is rather a result of inhomogeneities in the distribution of matter. In this dissertation, inhomogeneous models of the Universe are investigated on the basis of Lemaître-Tolman-Bondi (LTB) metric, which represents a spherical symmetry solution to dust. Two particular models are studied: the parabolic evolution with inhomogeneous Big Bang’s time and the of hyperbolic evolution with weak curvature and constant Big Bang’s time. The properties of each of these models are investigated in detail, as analitically as possible. Both models are compared with astrophysical observations of the sample Union2.1 SNIa. It is conclude that these models could be a starting point to develop more realistic models. Thus LTB solution is capable to explain the observed relationship between distance luminosity and redshift of supernovae without the requirement of dark energy when the inhomogeneity is either the form of an empty or there is a hill centered on the observer; with the further assumption that the outside Universe, in both cases, is approxinately described by the Einstein-de sitter homogeneous model.O modelo padrão atual da cosmologia, o modelo ΛCDM (Λ-Cold Dark Matter), está baseada nas soluções homogêneas de Friedmann-Lemaître-Robertson-Walker (FLRW) das equações de Einstein. As características da Cosmic Microwave Background (CMB) e da formação de estrutura em grandes escalas, são estudadas através da teoria das perturbações cosmológicas no fundo homogêneo e isotrópico. No entanto, nos últimos quinze anos, modelos cosmológicos inomogêneos "simples"que são generalizações do modelo cosmológico FLRW ganharam interesse na comunidade astrofísica e têm sido utilizados para estudar fenômenos cosmológicos. Alguns autores demonstraram que estes modelos inomogêneos com simetria esférica e com fonte de poeira podem reproduzir um bom ajuste para os dados de supernovas do tipo Ia (SNIa) e a posição do primeiro pico da CMB. Estes modelos sugerem que a aparente expansão acelerada do Universo não é causada pela gravidade repulsiva devido à energia escura, mas é sim o resultado das inomogeneidades na distribuição da matéria. Nesta dissertação, os modelos inomogêneos do Universo são investigados na base da métrica de Lemaître-Tolman-Bondi (LTB), o que representa uma solução com simetria esférica para poeira. Dois modelos particulares são estudados: a evolução parabólica com tempo de Big Bang inomogêneo e a evolução hiperbólica com curvatura fraca e tempo de Big Bang constante. As propriedades de cada um destes modelos são investigadas em detalhe, da forma mais analítica possível. Ambos modelos são confrontados com observações astrofísicas da amostra Union2.1 SNIa. Conclui-se que esses modelos podem ser um ponto de partida para desenvolver modelos mais realistas. Portanto, a solução de LTB é capaz de explicar a relação observada entre a distância de luminosidade e o desvio para o vermelho de supernovas sem a necesidade da energia escura quando a inomogeneidade é da forma de um vazio ou quando se tem uma colina centrada no observador com a suposição adicional de que o Universo fora do vazio ou fora da colina é aproximadamente descrito pelo modelo de Einstein-de Sitter homogéneo.TextISIDRO, Eddy Giusepe Chirinos. Modelos Simples de Lemaitre - Tolman - Bondi (LTB). 2015. Dissertação (Mestrado em Física) – Universidade Federal do Espírito Santo, Vitória, 2015.http://repositorio.ufes.br/handle/10/7459porUniversidade Federal do Espírito SantoMestrado em FísicaPrograma de Pós-Graduação em FísicaUFESBRCentro de Ciências ExatasCosmologyDark EnergySupernovae IaInhomogeneous Universe ModelsCosmologiaEnergia EscuraSupernovas IaUniverso InomogêneoFísica53Modelos Simples de Lemaitre - Tolman - Bondi (LTB)info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)instname:Universidade Federal do Espírito Santo (UFES)instacron:UFESORIGINALEddy-Giusepe-Chirinos-Isidro-2015-trabalho.pdfapplication/pdf19967431http://repositorio.ufes.br/bitstreams/0ffc18ab-e82a-4bfc-9bd7-f463fca4fde2/download09794aab73c65df0a113edc0844e46aeMD5110/74592024-06-28 18:06:29.294oai:repositorio.ufes.br:10/7459http://repositorio.ufes.brRepositório InstitucionalPUBhttp://repositorio.ufes.br/oai/requestopendoar:21082024-06-28T18:06:29Repositório Institucional da Universidade Federal do Espírito Santo (riUfes) - Universidade Federal do Espírito Santo (UFES)false |
dc.title.none.fl_str_mv |
Modelos Simples de Lemaitre - Tolman - Bondi (LTB) |
title |
Modelos Simples de Lemaitre - Tolman - Bondi (LTB) |
spellingShingle |
Modelos Simples de Lemaitre - Tolman - Bondi (LTB) Isidro, Eddy Giusepe Chirinos Cosmology Dark Energy Supernovae Ia Inhomogeneous Universe Models Cosmologia Energia Escura Supernovas Ia Universo Inomogêneo Física 53 |
title_short |
Modelos Simples de Lemaitre - Tolman - Bondi (LTB) |
title_full |
Modelos Simples de Lemaitre - Tolman - Bondi (LTB) |
title_fullStr |
Modelos Simples de Lemaitre - Tolman - Bondi (LTB) |
title_full_unstemmed |
Modelos Simples de Lemaitre - Tolman - Bondi (LTB) |
title_sort |
Modelos Simples de Lemaitre - Tolman - Bondi (LTB) |
author |
Isidro, Eddy Giusepe Chirinos |
author_facet |
Isidro, Eddy Giusepe Chirinos |
author_role |
author |
dc.contributor.author.fl_str_mv |
Isidro, Eddy Giusepe Chirinos |
dc.contributor.referee1.fl_str_mv |
Falciano, Felipe Tovar |
dc.contributor.referee2.fl_str_mv |
Marra, Valerio |
dc.contributor.referee3.fl_str_mv |
Piattella, Oliver Fabio |
contributor_str_mv |
Falciano, Felipe Tovar Marra, Valerio Piattella, Oliver Fabio |
dc.subject.eng.fl_str_mv |
Cosmology Dark Energy Supernovae Ia Inhomogeneous Universe Models |
topic |
Cosmology Dark Energy Supernovae Ia Inhomogeneous Universe Models Cosmologia Energia Escura Supernovas Ia Universo Inomogêneo Física 53 |
dc.subject.por.fl_str_mv |
Cosmologia Energia Escura Supernovas Ia Universo Inomogêneo |
dc.subject.cnpq.fl_str_mv |
Física |
dc.subject.udc.none.fl_str_mv |
53 |
description |
The current standard model of cosmology, the ?CDM model (?-Cold Dark Matter), is on the homogeneous solutions of Friedmann-Lemaître-Robertson-Walker (FLRW) of Einstein’s equations. The characteristics of the Cosmic Microwave Background (CMB) and structure formation on large scales are studied through the theory of cosmological perturbations in homogeneous and isotropic background. However, in the last fifteen years, "simple" inhomogeneous cosmological models that are generalizations of FLRW cosmological model gained interest in astrophysics community and have been used to study cosmological phenomena. Some authors have shown that these inhomogeneous models with spherical symmetry and dust source can play a good fit for the data type Ia supernovae (SNIa) and the position of the first peak of the CMB. These models suggest that the apparent accelerated expansion of the universe is not caused by the repulsive gravity due to dark energy, but is rather a result of inhomogeneities in the distribution of matter. In this dissertation, inhomogeneous models of the Universe are investigated on the basis of Lemaître-Tolman-Bondi (LTB) metric, which represents a spherical symmetry solution to dust. Two particular models are studied: the parabolic evolution with inhomogeneous Big Bang’s time and the of hyperbolic evolution with weak curvature and constant Big Bang’s time. The properties of each of these models are investigated in detail, as analitically as possible. Both models are compared with astrophysical observations of the sample Union2.1 SNIa. It is conclude that these models could be a starting point to develop more realistic models. Thus LTB solution is capable to explain the observed relationship between distance luminosity and redshift of supernovae without the requirement of dark energy when the inhomogeneity is either the form of an empty or there is a hill centered on the observer; with the further assumption that the outside Universe, in both cases, is approxinately described by the Einstein-de sitter homogeneous model. |
publishDate |
2015 |
dc.date.issued.fl_str_mv |
2015-05-07 |
dc.date.accessioned.fl_str_mv |
2018-08-01T22:29:42Z |
dc.date.available.fl_str_mv |
2018-08-01 2018-08-01T22:29:42Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
ISIDRO, Eddy Giusepe Chirinos. Modelos Simples de Lemaitre - Tolman - Bondi (LTB). 2015. Dissertação (Mestrado em Física) – Universidade Federal do Espírito Santo, Vitória, 2015. |
dc.identifier.uri.fl_str_mv |
http://repositorio.ufes.br/handle/10/7459 |
identifier_str_mv |
ISIDRO, Eddy Giusepe Chirinos. Modelos Simples de Lemaitre - Tolman - Bondi (LTB). 2015. Dissertação (Mestrado em Física) – Universidade Federal do Espírito Santo, Vitória, 2015. |
url |
http://repositorio.ufes.br/handle/10/7459 |
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por |
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openAccess |
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Text |
dc.publisher.none.fl_str_mv |
Universidade Federal do Espírito Santo Mestrado em Física |
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Programa de Pós-Graduação em Física |
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UFES |
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Centro de Ciências Exatas |
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Universidade Federal do Espírito Santo Mestrado em Física |
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