Accelerating Universe
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Interpersonal exchanges on the Internet: sociability and privacy in cyberculture / As trocas interpessoais na Internet: privacidade e sociabilidade na era da cibercultura
To analyze the phenomenon of exposure of privacy and sociability forms provided by Internet is the issue of this research. This is a study of the reasons that make a lot of people post their personal characteristics on Internet. It is a qualitative research with an exploratory and comprehensive nature. Its universe is composed by individuals who participate
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/08/2010
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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. Dark energy and cyclic universe from Arnowitt-Deser-Misner renormalizable group approach
We discuss the generic features of the accelerated universe from Arnowitt-Deser-Misner renormalizable group approach applied for gravity models with variable gravitational coupling constant and cosmological constant. The universe undergoes an endless sequence of cosmic eras which starts inflating after a Big Bang and end contracting to a Big Crunch dominated
Brazilian Journal of Physics. Publicado em: 2009-03
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4. 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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5. Alternative dark energy models: an overview
A large number of recent observational data strongly suggest that we live in a flat, accelerating Universe composed of ~ 1/3 of matter (baryonic + dark) and ~ 2/3 of an exotic component with large negative pressure, usually named Dark Energy or Quintessence. The basic set of experiments includes: observations from SNe Ia, CMB anisotropies, large scale struct
Brazilian Journal of Physics. Publicado em: 2004-03
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6. Dark energy and the accelerated expansion of the Universe
Recent observations indicate that the expansion of the Universe is accelerating. This suggests the existence of some kind of exotic matter with negative pressure. The simplest possibility is a cosmological constant but there are alternatives, as for instance an evolving scalar field. In this paper we explore constraints from lensing statistics and high-z typ
Brazilian Journal of Physics. Publicado em: 2000-06
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7. An introduction to quintessence
There is a missing energy problem in cosmology: the total energy density of the Universe, based on a wide range of observations, is much greater than the energy density contributed by all baryons, neutrinos, photons, and dark matter. Deepening this mystery are the recent observations of type 1a supernovae which suggest that the expansion rate of the Universe
Brazilian Journal of Physics. Publicado em: 2000-06
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8. 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.
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9. Hubble's diagram and cosmic expansion
Edwin Hubble's classic article on the expanding universe appeared in PNAS in 1929 [Hubble, E. P. (1929) Proc. Natl. Acad. Sci. USA 15, 168–173]. The chief result, that a galaxy's distance is proportional to its redshift, is so well known and so deeply embedded into the language of astronomy through the Hubble diagram, the Hubble constant, Hubble's Law, and
National Academy of Sciences.