搜索结果: 1-15 共查到“天文学 Constant”相关记录15条 . 查询时间(0.277 秒)
Holographic Dark Energy Characterized by the Total Comoving Horizon and Insights to Cosmological Constant and Coincidence Problem
Holographic Dark Energy the Total Comoving Horizon Insights Cosmological Constant Coincidence Problem
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2012/2/21
The observed acceleration of the present universe is shown to be well explained by the holographic dark energy characterized by the total comoving horizon of the universe ($\eta$HDE). It is of interes...
Future constraints on variations of the fine structure constant from combined CMB and weak lensing measurements
Future constraints variations fine structure constant combined CMB weak lensing measurements
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2012/2/21
We forecast the ability of future CMB and galaxy lensing surveys to constrain variations of the fine structure constant. We found that lensing data, as those expected from satellite experiments as Euc...
The Cosmological Constant in the Quantum Multiverse
Cosmological Constant Quantum Multiverse
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2011/10/17
Recently, a new framework for describing the multiverse has been proposed which is based on the principles of quantum mechanics. The framework allows for well-defined predictions, both regarding globa...
Inflation and the cosmological constant
general relativity infl ationary universe cosmological constant
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2011/10/14
A particular compensation-type solution of the main cosmological constant problem has been proposed recently, with two massless vector fields dynamically canceling an arbitrary cosmological constant \...
The WiggleZ Dark Energy Survey: constraining the evolution of Newton's constant using the growth rate of structure
constraining evolution constant using growth rate structure
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2011/10/11
We constrain the evolution of Newton's constant using the growth rate of large-scale structure measured by the WiggleZ Dark Energy Survey in the redshift range $0.1 < z < 0.9$. We use this data in two...
The Hubble Constant measured from the anisotropy in the cosmic microwave background (CMB) is shown to be independent of small changes from the standard model of the redshift dependence of dark energy....
The Poincare Conjecture and the Cosmological Constant
Manifold Deformations Poincar Conjecture Cos- mological Constant
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2011/10/17
The concept of deformation of Riemannian geometry is reviewed, with applications to gravitation and cosmology. Starting with an analysis of the cosmological constant problem, it is shown that space-ti...
Domain wall solution in $F(R)$ gravity and variation of the fine structure constant
solution gravity variation fine structure
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2011/10/18
We construct a domain wall solution in $F(R)$ gravity. We first compare a scalar field theory having a runaway type potential with a corresponding scalar field theory obtained through a conformal tran...
The cosmological constant and the relaxed universe
The cosmological constant the relaxed universe
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2011/1/13
We study the role of the cosmological constant (CC) as a component of dark energy (DE). It is argued that the cosmological term is in general unavoidable and it should not be ignored even when dynami...
We address the issue why a cosmological constant (dark energy) possesses a small positive value instead of being zero. Motivated by the cosmic landscape picture, we mimic the dark energy by a scalar f...
Solar System Motions and the Cosmological Constant：jA New Approach
Solar System Motions jA New Approach Cosmological Constant
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2009/9/4
We use the corrections to the Newton-Einstein secular precessions of the longitudes of perihelia ϖ˙ of some planets (Mercury, Earth, Mars, Jupiter, Saturn) of the Solar System, phenomenologically...
A Simple Model for Hydromagnetic Instabilities in the Presence of a Constant Magnetic Field
Hydromagnetic Instabilities Constant Magnetic Field
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2009/6/25
A Simple Model for Hydromagnetic Instabilities in the Presence of a Constant Magnetic Field。
A MODIFIED THEORETICAL Sigma-D RELATION FOR SUPERNOVA REMNANTS：I. THE CASE OF CONSTANT TEMPERATURE WITHIN THE SUPERNOVA REMNANT
ISM supernova remnants-radiation mechanisms thermal-radio continuum ISM
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2009/3/13
We present a modification of the theoretical Σ − D relation for
supernova remnants (SNRs) in the adiabatic expansion phase. This modification
is based on the convolution of the relation first ...
Notes on the Quantization of FRW Model in the Presence of a Cosmological Constant and Radiation
FRW Model a Cosmological Constant
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2010/10/18
In the present work, we use the formalism of quantum general relativity in order to quantize a Friedmann-Robertson-Walker model in the presence of a negative cosmological constant and radiation. The m...
Neutrino Mixing as a Source for Cosmological Constant
Neutrino Mixing Cosmological Constant
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2010/10/14
We report on recent results showing that neutrino mixing may lead to a non-zero contribution to the cosmological constant. This contribution is of a completely different nature with respect to the usu...