Showing papers on "Big Rip published in 1972"
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95 citations
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TL;DR: In this article, a detailed multicomponent model is developed for dissipative processes in Euclidean homogeneous cosmological models, which involve neutrinos which might have long mean free times in interaction with other constituents which are thermalized by electromagnetic interactions.
Abstract: Consideration of dissipative processes in anisotropic homogeneous world models, showing that dissipation reduces the anisotropy. The viscosity approximation and its range of applicability is discussed. Examples are presented which have been calculated by the use of a simple approximation to the collision-time method, using the cross section appropriate to weak interaction neutrino scattering. It is found that such dissipation is quite effective except for one particular cosmological model which is axisymmetric and in which the entire expansion of the model is taken up by expansion along the axis. A detailed multicomponent model is developed for dissipative processes in Euclidean homogeneous cosmological models. These processes involve neutrinos which might have long mean free times in interaction with other constituents which are thermalized by electromagnetic interactions, and whose weak interactions produce thermal neutrinos.
35 citations
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18 citations
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TL;DR: In this article, the generalized covariant Dirac equation for a certain five-dimensional universe is studied and it is shown that particle-like stable solutions exist having definite positive rest energy, spin, and corresponding antiparticles.
Abstract: The generalized covariant Dirac equation for a certain five‐dimensional universe is studied. If a torsion invariant is included in the free Lagrangian, it is shown that particlelike stable solutions exist having definite positive rest energy, spin, and corresponding antiparticles. The treatment is throughout classical.
15 citations
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11 citations
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10 citations
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TL;DR: In this article, the authors derived a new exact solution to Einstein's equations representing homogeneous nonisotropic cosmological models of a closed universe containing electromagnetic and scalar fields, which reduces to a generalization of Brill's electromagnetic universe when the scalar field vanishes, and to the Taub-NUT-M space when both these fields vanish.
8 citations
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TL;DR: In this paper, the field equations of a noncovariant theory of gravitation, based on the existence of a preferred frame of reference in the universe, are applied to the homogeneous isotropic cosmological model.
Abstract: The field equations of a noncovariant theory of gravitation, based on the existence of a preferred frame of reference in the universe, are applied to the homogeneous isotropic cosmological model. One is naturally led to a particular value of the previously undetermined constant present in the equations. The second-order equation determining the radius of the universe can be integrated to give a first-order equation similar to that of general relativity, but with an additional term that can lead to oscillations without any singular state. One obtains a conservation law for the total energy, which is found to be positive definite.
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TL;DR: In this paper, a formalism for dealing with various non-linear effects of cosmic fluid being important during the formation of galaxies is developed in comparison with the previous one based on the general relativistic cosmology.
Abstract: In view of a possible relevance of the scalar-tensor theory of gravity to various cosmo logical and astrophysical problems, Newtonian hydrodynamics suitable at the matter dominant stage of the Brans-Dicke universe is formulated and a formalism for dealing with various non-linear effects of cosmic fluid being important during the formation of galaxies is devel oped in comparison with the previous one based on the general relativistic cosmology. In contrast with the situation in the linear theory of gravitational instability, it is shown in the case of a density perturbation with spherical symmetry that the critical epoch and density ratio for the occurrence of gravitational binding at the center may considerably be different from those in the Friedmann universe. Dynamical equations for a rotating gaseous ellipsoid with uniform density are also derived and their general features are touched upon.
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TL;DR: The quantity of mass energy in the universe is expressed in terms of some of its basic parameters as mentioned in this paper, and the methods of derivation involve the minimum possible unit of energy and minimum possible non-zero force, introduced in a previous paper by Crocker, 1970.
Abstract: The quantity of mass-energy in the universe is expressed in terms of some of its basic parameters. The methods of derivation involve the minimum possible unit of energy and the minimum possible non-zero force, introduced in a previous paper (in this journal) by the author (Crocker, 1970).
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TL;DR: In this article, a fluid homogeneous cosmologioal model with a Robertson-Walker metric and positive curvature is proposed, which affords an interpretation to the matter production process in the following terms.
Abstract: A fluid homogeneous cosmologioal model is proposed with a Robertson-Walker metric and positive curvature. The Einstein field equations are modified through the following two assumptions: the principle of Mach in Whitrow’s formulation and a new version of Hoyle’s vector field. The present model affords an interpretation to the matter production process in the following terms: the matter injection into the observable universe is due to the work done along cosmic expansion by a negative-pressure substratum and to the variation of a negative field energy. The properties of the expansion function and the vector field demand a negative cosmological constant.