Acceleration Of The Universe
Mostrando 1-10 de 10 artigos, teses e dissertações.
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1. Uma descrição da expansão e aceleração do universo no contexto das teorias f(R) / A description of expansion and acceleration of the universe in the context of f(R) theories
Diante das observações experimentais da expansão cósmica acelerada, diversos - modelos teóricos surgiram para explicar a aceleração do Universo. Neste trabalho revisamos modelos tais como a constante cosmológica e quintessência, a qual é modelada por um campo escalar. O contexto aqui apresentado foi elaborado a partir das teorias modificadas da gra
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/02/2012
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2. Dark Energy and The Accelerating Universe: Conceptual Aspects and Observational Tests / Energia escura e aceleração do Universo: Aspectos conceituais e testes observacionais
In the last decade, the extraordinary progress of the astronomical observations (distances with supernovas, matter and cosmic background radiation (CBR) power spectrum, X-ray surface brightness of galaxy clusters, etc) associated with important theoretical developments turned Cosmology one of the most exciting frontiers of contemporary science. In this thesi
Publicado em: 2010
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3. Estudo de anisotropias de UHECR s em dados do Observatorio Pierre Auger / Study of anisotropies of cosmic rays in data from the Pierre Auger
Almost a century after the discovery of cosmic radiation, their origin, composition, acceleration and propagation mechanisms in the universe is still unknown for the ultra-high energy component ( >~ 1018 eV). The mystery grows due to the suppression (GZK cutoff) in the ux of cosmic rays with energies E >~ 6 × 10 19 eV, caused by the interaction of these par
Publicado em: 2009
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4. Trilogia Qatsi : visões e movimentos de mundo / Qatsi trilogy : visions and movements of world
This work is a filmic analysis of the Qatsi trilogy (Koyaanisqatsi, Powaqqatsi, Naqoyqatsi), directed by Godfrey Reggio. Firstly, it is presented a bio-filmography of the director, indicating his trajectory and some comments on each of his films. Then, the analysis of the trilogy takes place, beginning with Koyaanisqatsi and focusing the acceleration movemen
Publicado em: 2009
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5. Acelaração do universo e criação gravitacional de matéria escura fria: novos modelos e testes observacionais
Recent astronomical observations (involving supernovae type Ia, cosmic background radiation anisotropy and galaxy clusters probes) have provided strong evidence that the observed universe is described by an accelerating, flat model whose space-time properties can be represented by the FriedmannRobertsonWalker (FRW) metric. However, the nature of the substanc
Publicado em: 2008
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6. Growing of the inhomogeneities and acceleration phase in a universe with lambda decay
We study a model with decay of dark energy and creation of the dark matter particles. We integrate the field equations and find the transition redshift where the evolution process of the universe change from decelerated to an accelerated phase expansion, and briefly discuss the transition epoch and the broken of the strong energy condition. Finally, we exami
Brazilian Journal of Physics. Publicado em: 2007-12
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7. Educação inclusiva é para todos? a (falta de) formação docente para altas habilidades/superdotação no Brasil / Is Inclusive Education for everybody? The (lack of) teaching formation to High Abilities/Highygifted in Brazil
This study aimed at the analysis of some aspects related to the teaching formation on Special Education, High Abilities and to the Highlygifted, that make up the necessary and desirable competences to meet the universe of Inclusive Education. The research was characterized by the case study, where academic pedagogic procedures were analyzed related to the fo
Publicado em: 2006
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8. Is the cosmological particle production homogeneous?
Using a gauge-invariant formalism we find the density contrast equation in a cosmological scenario with particle production at the expenses of the gravitational field (open system cosmology). First, we find the modes for the density contrast considering that the particle production process participate of the inhomogeneities formation, and in a second phase t
Brazilian Journal of Physics. Publicado em: 2005-12
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9. Irreversible processes and the accelerated-decelerated phases of the Universe
A model for the Universe is proposed where it is considered as a mixture of scalar and matter fields. The particle production is due to an irreversible transfer of energy from the gravitational field to the matter field and represented by a non-equilibrium pressure. This model can simulate three distinct periods of the Universe: (a) an accelerated epoch wher
Brazilian Journal of Physics. Publicado em: 2004-09
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10. Supernovae, an accelerating universe and the cosmological constant
Observations of supernova explosions halfway back to the Big Bang give plausible evidence that the expansion of the universe has been accelerating since that epoch, approximately 8 billion years ago and suggest that energy associated with the vacuum itself may be responsible for the acceleration.
The National Academy of Sciences.