Showing papers on "Particle horizon published in 1976"
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TL;DR: In this article, the authors distinguish between two separate questions: 1) must the universe be symmetric and 2) does an application of the microscopic laws of physics to the macroscopic scale of the universe require that there be exactly equal numbers of particles and antiparticles.
Abstract: In approaching the problem of the amount and astrophysical role of antimatter in the Universe, it is valuable to distinguish between two separate questions. First, must the universe be symmetric. Does an application of the microscopic laws of physics to the macroscopic scale of the Universe require that there be exactly equal numbers of particles and antiparticles. In contrast, is the Universe symmetric. The extent to which these questions can be or have been answered is the subject of this review. 2 tables, 118 refs. (GHT)
279 citations
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62 citations
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TL;DR: In this paper, the effect of particle creation in homogeneous anisotropic models is considered, and the back reaction of the created particles on the metric is taken into account, as a result, the expansion of the universe becomes quasi-isotropic (with small vortex perturbations) starting from the Planck time 10−43s.
Abstract: The effect of particle creation in homogeneous anisotropic models is considered. The back reaction of the created particles on the metric is taken into account. As a result, the expansion of the Universe becomes quasi-isotropic (with small vortex perturbations) starting from the Planck time 10−43s. After some intermediate damping stage the cosmological expansion approaches the Friedmann isotropic model. Observational consequences are discussed.
39 citations
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TL;DR: In this paper, plausible cosmological models are examined with respect to measurements of deceleration, the age of the universe, the average density of matter, and the abundance of deuterium.
Abstract: Plausible cosmological models are examined with respect to measurements of deceleration, the age of the universe, the average density of matter, and the abundance of deuterium. These factors together indicate that the expansion of the universe cannot be halted or reversed, that the universe is open. (BJG)
21 citations
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TL;DR: The quark theory of hadrons provides a valuable tool for interpreting conditions during early epochs of the Universe as discussed by the authors, and an asymptotically free theory of quarks seems to rule out the possibility that the present-day entropy of the universe could be due to dissipation of low level fluctuations.
Abstract: The quark theory of hadrons provides a valuable tool for interpreting conditions during early epochs of the Universe. In particular, an asymptotically free theory of quarks seems to rule out the possibility that the present-day entropy of the Universe could be due to dissipation of low level fluctuations. Apparently either the early Universe was inhomogeneous on small mass scales or anisotropic.
17 citations
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TL;DR: In this article, an attempt is made to derive propagators for a massive scalar field in the Kasner universe, where the propagation structure depends also on the structure of the universe.
Abstract: In view of a recent interest in the quantum field-theoretical creation of particles in a big-bang universe (which, via the problem of how their vacuum state should be defined, will be connected with their propagators whose structure depends also on that of the Universe), an attempt is made to derive propagators for a massive scalar field in the Kasner universe.
11 citations
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6 citations
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6 citations
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4 citations
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TL;DR: In this paper, it was shown that a uniformly expanding universe exhibits a velocity space described by the hyperbolic geometry of J. Bolyai and N. Lobachevsky.
Abstract: It is shown that a uniformly-expanding universe, governed by the Cosmological Principle, exhibits a velocity space described by the hyperbolic geometry ofJ. Bolyai andN. Lobachevsky. This geometry provides a mathematical description of the free paths of lightrays and of material bodies, and has considerable theoretical, epistemological and practical implications. Its application is of particular importance for astronomical observations involving cosmological distances; this is exemplified in relation to the estimation of the size of objects (QSOs) with large (z>1) redshifts. It is suggested that Bolyai—Lobachevskian geometry is of general relevance to any expanding model of the universe.