Cosmic Microwave Background Cmb
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Calibration of the GEM synchrotron emission map using the ARCADE 2 experiment data / Calibração do mapa de emissão síncrotron do radiotelescópio GEM utilizando os dados de temperatura absoluta do experimento ARCADE 2
The motivation of this work is to produce a synchrotron emission map in a range of frequencies not yet well mapped, between 408 MHz and 23 GHz, in order to assist the foreground separation process on the data analysis of the Cosmic Microwave Background (CMB) radiation. We used the data from GEM (Galactic Emission Mapping) telescope, whose dominant processes
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 24/02/2011
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2. Cosmic microwave background polarization / Polarização da radiação cósmica de fundo
Applying concepts of quantum mechanics and kinetic theory we show a re-derivation of Boltzmann equation for the Cosmic Microwave Background (CMB) polarization. We show the equivalence between our derivation and those already known ( [1], [2], [3] ) and also that these derivations correspond to take into account the effect, on the photon polarization, of two
Publicado em: 2009
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3. Thermodynamic properties of the field electromagnetic field in the CPT-odd standard extended / Propriedades termodinâmicas do campo eletromagnético no setor CPT-ımpar do modelo padrão estendido
In this work we study the effects of the spontaneous breaking of Lorentz symmetry on black body radiation phenomenon in the context of the Maxwell-Caroll-Field-Jackiw (MCFJ) model. The MCFJ model is the electromagnetic CPT-odd sector of the standard model extension and, it presents for a purely space-like background a positive-definite hamiltonian. Firstly,
Publicado em: 2009
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4. Fundo estocástico de ondas gravitacionais gerados por buracos negros pré-galáctiocs / Stochastic Background of Gravitational Waves Generated By pre-galactic Black Hole Formation
Observation of the Cosmic Microwave Background Radiation (CMB) provide us with a clear information about the status of matter and radiation at the decoupling era like a snapshot of the Universe 300.000 years after the Big-Bang. Nowadays, through observations of the cosmic structure, we can build-up the history of the Universe from one billion years after the
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/02/2008
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5. Fundo estocástico de ondas gravitacionais gerados por buracos negros pré-galáctiocs / Stochastic Background of Gravitational Waves Generated By pre-galactic Black Hole Formation
Observation of the Cosmic Microwave Background Radiation (CMB) provide us with a clear information about the status of matter and radiation at the decoupling era like a snapshot of the Universe 300.000 years after the Big-Bang. Nowadays, through observations of the cosmic structure, we can build-up the history of the Universe from one billion years after the
Publicado em: 2008
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6. Polarization in the cosmic microwave background
Cosmic microwave background (CMB) studies underpin our understanding of the universe and its history. Until recently, we have relied principally on CMB temperature observations to build our standard cosmological model, but today the field forges ahead into its next frontier - CMB polarization anistropy. Polarization measurements will furnish fresh and indepe
Brazilian Journal of Physics. Publicado em: 2006-12
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7. The shape of space after WMAP data
What is the shape of space is a long-standing question in cosmology. I review recent advances in cosmic topology since it has entered a new era of experimental tests. High redshift surveys of astronomical sources and accurate maps of the Cosmic Microwave Background radiation (CMB) are beginning to hint at the shape of the universe, or at least to limit the w
Brazilian Journal of Physics. Publicado em: 2006-03
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8. The large-scale angular correlations in CMB temperature maps
Observations show that the Cosmic Microwave Background (CMB) contains tiny variations at the 10-5 level around its black-body equilibrium temperature. The detection of these temperature f luctuations provides to modern Cosmology evidence for the existence of primordial density perturbations that seeded all the structures presently observed. The vast majority
Brazilian Journal of Physics. Publicado em: 2005-12
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9. Strong limits on the possible decay of the vacuum energy into CDM or CMB photons
We investigate models that suggest that the vacuum energy could decay into cold dark matter (CDM) or into a homogeneous distribution of thermalized cosmic microwave background (CMB) photons. We show that the agreement of the density fluctuation spectra obtained from the CMB and galaxy distribution data puts strong limits on the rate of vacuum energy decay. A
Brazilian Journal of Physics. Publicado em: 2005-12
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10. Gravitational waves: a 100-year tool applied to the dark energy problem
Recent observations from type Ia Supernovae and from cosmic microwave background (CMB) anisotropies have revealed that most of the matter of the Universe interacts in a repulsive manner, composing the so-called dark energy constituent of the Universe. Determining the properties of dark energy is one of the most important tasks of modern cosmology and this is
Brazilian Journal of Physics. Publicado em: 2005-12
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11. Um processo Otimizado de produção de mapas da radiação cósmica de fundo em microondas / An optimized process of production of cosmic microwave backgroud radiation maps
The current work describes the optimization and parallelization of the software for the production of Cosmic Microwave Background (CMB) radiation maps in a distributed memory architecture. Initially, the Fortran code was ported to Fortran 90 and to High Performance Fortran (HPF) and run in a SMP (Shared Memory Processor) machine. In order to provide timing i
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/03/2003
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12. Cosmic microwave background theory
A long-standing goal of theorists has been to constrain cosmological parameters that define the structure formation theory from cosmic microwave background (CMB) anisotropy experiments and large-scale structure (LSS) observations. The status and future promise of this enterprise is described. Current band-powers in ℓ-space are consistent with a ΔT fl
National Academy of Sciences.