Results 31 to 40 of about 6,695,532 (296)
An alternative to the cosmological “concordance model” [PDF]
Astronomy & Astrophysics, 2003 Precision measurements of the cosmic microwave background by WMAP are believed to have established a flat $Λ$-dominated universe, seeded by nearly scale-invariant adiabatic primordial fluctuations. However by relaxing the hypothesis that the fluctuation spectrum can be described by a single power law, we demonstrate that an Einstein-de Sitter universe ...
Blanchard, Alain +3 more
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Homogeneous Cosmological Models in Weyl’s Geometrical Scalar–Tensor Theory
Universe, 2023 In this paper, we consider homogeneous cosmological solutions in the context of the Weyl geometrical scalar–tensor theory. Firstly, we exhibit an anisotropic Kasner type solution taking advantage of some similarities between this theory and the Brans ...
Adriano Barros, Carlos Romero
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Cosmological consequences of a variable cosmological constant model [PDF]
International Journal of Modern Physics D, 2016 We derive a model of dark energy which evolves with time via the scale factor. The equation-of-state is studied as a function of a parameter [Formula: see text] introduced in this model as [Formula: see text]. In addition to the recent accelerated expansion, the model predicts another decelerated phase.
Azri, Hemza, Bounames, A.
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Physics, 2021 In this paper, the effects of the quantum metric fluctuations on the background cosmological dynamics of the universe are considered. To describe the quantum effects, the metric is assumed to be given by the sum of a classical component and a fluctuating
Zahra Haghani, Tiberiu Harko
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Fractal Bubble cosmology: a concordant cosmological model? [PDF]
Monthly Notices of the Royal Astronomical Society: Letters, 2009 Abstract The Fractal Bubble model has been proposed as a viable cosmology that does not require dark energy to account for cosmic acceleration, but rather attributes its observational signature to the formation of structure. In this Letter, it is demonstrated that, in contrast to previous findings, this model is not a good fit to ...
Kwan, Juliana +2 more
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Singularities in Inflationary Cosmological Models
Universe, 2021 Due to the accelerated expansion of the universe, the possibilities for the formation of singularities has changed from the classical Big Bang and Big Crunch singularities to include a number of new scenarios. In recent papers it has been shown that such
Leonardo Fernández-Jambrina
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The standard cosmological model [PDF]
Canadian Journal of Physics, 2006 The Standard Model of Particle Physics (SMPP) is an enormously successful description of high-energy physics, driving ever more precise measurements to find "physics beyond the standard model", as well as providing motivation for developing more fundamental ideas that might explain the values of its parameters.
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A Generalized Solution of Bianchi Type-V Models with Time-Dependent G and Λ
Universe, 2018 We study the homogeneous but anisotropic Bianchi type-V cosmological model with time-dependent gravitational and cosmological “constants”. Exact solutions of the Einstein field equations (EFEs) are presented in terms of adjustable parameters ...
Alnadhief H. A. Alfedeel +2 more
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Quantum cosmological models [PDF]
Classical and Quantum Gravity, 2005 revised: now includes time asymmetry, black hole final state etc, 71 ...
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Scalar-tensor cosmological models [PDF]
Physical Review D, 1996 uuencoded compressed postscript file containing 41 pages, with 9 figures, accepted for publication in Physical Review ...
Serna, Arturo, Alimi, Jean-Michel
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