Solving the flatness and quasi-flatness problems in Brans-Dicke cosmologies with a varying light speed
نویسندگان
چکیده
منابع مشابه
Solving the Flatness and Quasi-flatness Problems in Brans-Dicke Cosmologies with a Varying Light Speed
The observable universe is close to a flat Friedmann model, the so-called Einstein-de Sitter universe, in which the energy density, ρ, takes the critical value, ρc, and the homogeneous spatial surfaces are Euclidean. All astronomical evidence shows that we are quite close to this state of flatness, although a value of Ω0 in the vicinity of 0.2 is preferred by several observations. It is therefo...
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Big Bang models of the Universe predict rapid domination by curvature, a paradox known as the flatness problem. Solutions to this problem usually leave the Universe exactly flat for every practical purpose. Explaining a nearly but not exactly flat current Universe is a new problem, which we label the quasi-flatness problem. We show how theories incorporating time-varying coupling constants coul...
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Recently, the matter field can give rise to an accelerated expansion [1] for the universe stems from the observational data regarding the luminosity-redshift relation of type Ia supernovae [2,3] up to about z ∼ 1. This matter field is called ’quintessence matter’ (shortly Q-matter). This Q-matter can behave like a cosmological constant [4,5] by combining positive energy density and negative pre...
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ژورنال
عنوان ژورنال: Classical and Quantum Gravity
سال: 1999
ISSN: 0264-9381,1361-6382
DOI: 10.1088/0264-9381/16/4/030