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Particle horizon

About: Particle horizon is a research topic. Over the lifetime, 2096 publications have been published within this topic receiving 69137 citations.


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TL;DR: In this article, the time dependence of G is presented and the mass distribution at large scales and the correlation function are explained and are natural consequences of the evaluated varying G. The results suggest a universe based on El Naschie's e(∞) Cantorian space time.
Abstract: In this paper the time dependence of G is presented. It is a simple consequence of the Virial Theorem and of the self-similarity and fractality of the Universe. The results suggest a Universe based on El Naschie’s e(∞) Cantorian space–time. Moreover, we show the importance of the Golden Mean in respect to the large scale structures. Thanks to this study the mass distribution at large scales and the correlation function are explained and are natural consequences of the evaluated varying G. We demonstrate the agreement between the present hypotheses of segregation with a size of astrophysical structures, by using a comparison between quantum quantities and astrophysical ones. It appears clear that the Universe has a memory of its quantum origin. This appears in the G dependence too. Moreover, we see that a G=G(t) in El Naschie’s e(∞) Cantorian space–time can imply an accelerated Universe.

51 citations

Journal ArticleDOI
TL;DR: In this article, it is shown that in the k = 0 FRW space, an impulse bulk viscosity ςinfl ~ 1060 g cm−1 s−1) acting at the phase transition at the end of the inflationary epoch corresponds to the correct entropy.
Abstract: Some aspects of viscous cosmological models, mainly of Bianchi type-I, are studied, in particular with the purpose of trying to obtain a natural explanation of why the entropy per baryon in the universe,σ ~ 109, is so large. Using the FRW metric it is first shown, in agreement with previous workers, that the expressions for the bulk viscosity as derived from kinetic theory in the plasma era is incapable of explaining the large value ofσ. However it is possible to imagine the viscosity to be an “impulse” viscosity operative in one or several phase transitions in the early universe. This is the main idea elaborated on in the present paper. It is shown that in thek = 0 FRW space, an impulse bulk viscosity ςinfl ~ 1060 g cm−1 s−1) acting at the phase transition at the end of the inflationary epoch corresponds to the correct entropy. If the space is anisotropic, it is natural to exploit the analogy with classical fluid dynamics to introduce the turbulent viscosity concept. This is finally discussed, in relation to an anisotropy introduced in the universe via the Kasner metric.

51 citations

Journal ArticleDOI
TL;DR: In this article, the implications for magnetic monopole production of a first-order phase transition in the evolution of the early universe are discussed, and the implications of such a phase transition for the generation of a baryon excess are discussed.

51 citations

Journal ArticleDOI
TL;DR: In this article, the cosmological constant was shown to be stable even when the potential has deeper minima, provided there was a period in which the temperature was ≳ 1 TeV.

51 citations

Journal ArticleDOI
TL;DR: In this article, the mass power spectrum for a universe dominated by the Chaplygin gas is evaluated numerically from scales of the order of the Hubble horizon to 100 Mpc, and the results are compared with a pure baryonic model and a cosmological constant model.
Abstract: The mass power spectrum for a Universe dominated by the Chaplygin gas is evaluated numerically from scales of the order of the Hubble horizon to 100 Mpc. The results are compared with a pure baryonic Universe and a cosmological constant model. In all three cases, the spectrum increases with k, the wavenumber of the perturbations. The slope of the spectrum is higher for the baryonic model and smaller for the cosmological constant model, the Chaplygin gas interpolating these two models. The results are analyzed in terms of the sound velocity of the Chaplygin gas and the moment the Universe begins to accelerate.

51 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202320
202247
20216
202010
201910
201814