Showing papers on "Big Rip published in 1985"
TL;DR: A scale-free spectrum of density perturbations which could account for the origin of galaxies and all other structure in the Universe is obtained.
Abstract: It is assumed that the Universe is in the quantum state defined by a path integral over compact four-metrics. This can be regarded as a boundary condition for the wave function of the Universe on superspace, the space of all three-metrics and matter field configurations on a three-surface. We extend previous work on finite-dimensional approximations to superspace to the full infinite-dimensional space. We treat the two homogeneous and isotropic degrees of freedom exactly and the others to second order. We justify this approximation by showing that the inhomogeneous or anisotropic modes start off in their ground state. We derive time-dependent Schr\"odinger equations for each mode. The modes remain in their ground state until their wavelength exceeds the horizon size in the period of exponential expansion. The ground-state fluctuations are then amplified by the subsequent expansion and the modes reenter the horizon in the matter- or radiation-dominated era in a highly excited state. We obtain a scale-free spectrum of density perturbations which could account for the origin of galaxies and all other structure in the Universe. The fluctuations would be compatible with observations of the microwave background if the mass of the scalar field that drives the inflation is ${10}^{14}$ GeV or less.
572 citations
TL;DR: If the decay of a massive relic species follows the usual exponential decay law, then the Universe is never reheated, rather it cools more slowly, and the usual estimates for the entropy increase are found to be correct.
Abstract: It is usually assumed that a massive relic species, which comes to dominate the mass density of the Universe and later decays, ``heats up'' the Universe when the age of the Universe \ensuremath{\simeq} its lifetime. We show that if its decay follows the usual exponential decay law, then the Universe is never reheated, rather it just cools more slowly. We calculate the evolution of the temperature and entropy, and find that to within numerical factors of order unity, the usual estimates for the entropy increase are correct. Our results have implications for primordial nucleosynthesis in scenarios where a massive relic with lifetime \ensuremath{\simeq} ${10}^{\mathrm{\ensuremath{-}}2}$--${10}^{3}$ sec is present, and for baryogenesis in the new inflationary Universe scenario.
234 citations
TL;DR: The usual proof of the CPT theorem does not apply to theories which include the gravitational field but it is shown that CPT invariance still holds in these cases provided that the quantum state of the Universe is defined by a path integral over metrics that are compact without boundary.
Abstract: The usual proof of the CPT theorem does not apply to theories which include the gravitational field. Nevertheless, it is shown that CPT invariance still holds in these cases provided that, as has recently been proposed, the quantum state of the Universe is defined by a path integral over metrics that are compact without boundary. The observed asymmetry or arrow of time defined by the direction of time in which entropy increases is shown to be related to the cosmological arrow of time defined by the direction of time in which the Universe is expanding. It arises because in the proposed quantum state the Universe would have been smooth and homogeneous when it was small but irregular and inhomogeneous when it was large. The thermodynamic arrow would reverse during a contracting phase of the Universe or inside black holes. Possible observational tests of this prediction are discussed.
159 citations
72 citations
TL;DR: In this paper, the first few orders of the Wheeler-DeWitt equations for the wave function of the universe in 2+1 and 3+1 dimensions were calculated for the case of an inflating universe.
50 citations
TL;DR: In this article, the cosmological equations are reduced to quadratures under the assumption of a power law between the expansion factor of the universe and the scalar field of the second self-creation theory proposed by G. A. Barber.
Abstract: Under the assumption of a power law between the expansion factor of the Universe and the scalar field of the second self-creation theory proposed by G. A. Barber, the cosmological equations are reduces to quadratures. Several exact solutions are obtained, among them linearly expanding and inflationary universes with a barotropic equation of state.
37 citations
TL;DR: The cold matter scenario for galaxy formation solves the dark matter problem very nicely on small scales corresponding to galaxies and clusters of galaxies as discussed by the authors, however, it is difficult to reconcile with a universe with an Einstein-deSitter value of (UC OMEGA) = 1.
Abstract: The cold matter scenario for galaxy formation solves the dark matter problem very nicely on small scales corresponding to galaxies and clusters of galaxies. It is, however, difficult to reconcile with a Universe with an Einstein-deSitter value of (UC OMEGA) = 1. Cold matter and (UC OMEGA) = 1 can be made compatible while retaining the feature that the Universe is matter dominated today. This is done by means of heavy (cold) particles whose decay subsequently leads to the unbinding of a large fraction of lighter clustered matter.
23 citations
TL;DR: In this paper, different interpretations of the rotation of the metagalaxy and cosmological models of the universe with rotation are considered, starting from the hierarchic concept of reality.
Abstract: We consider different interpretations of the rotation of the metagalaxy and cosmological models of the universe with rotation. The Muradyan formula for the angular momentum of the metagalaxy is obtained, starting from the hierarchic concept of reality. It is established that the angular velocities of rotation of matter in the Gedel and Ozsvath-Schucking models of the universe have the same order ∿10−11 rad/year. Possible local effects of a rotating universe are discussed.
16 citations
TL;DR: In this paper, it was shown that there exists a limiting density of matter of the order of magnitude of the Planck density at the moment at which the universe began to expand.
Abstract: Attention is given to the so-called standard model of the universe in the framework of the general theory of relativity. This model is taken to be homogeneous and isotropic and filled with an ideal fluid characterized by a density and a pressure. Taking into consideration, however, the assumption that the universe began in a singular state, it is found hard to understand why the universe is so nearly homogeneous and isotropic at present for a singularity represents a breakdown of physical laws, and the initial singularity cannot, therefore, predetermine the subsequent symmetries of the universe. The present investigation has the objective to find a way of avoiding this initial singularity, i.e., to look for a cosmological model without the big bang. The idea is proposed that there exists a limiting density of matter of the order of magnitude of the Planck density, and that this was the density of matter at the moment at which the universe began to expand.
14 citations
TL;DR: In this paper, the effects of classically unstable fields on the evolution of an open universe were considered and it was shown that such fields can cause the open universe to cease expanding and recollapse to a final singularity even if the total mass density is less than the critical density at the present time.
5 citations
TL;DR: A quantum cosmological model of the inflationary universe is investigated by solving the Wheeler-DeWitt equation, and in a certain parameter range a big peak is formed near the maximum of the double-well potential of the scalar field, accompanied by a recession of the exponential behavior of the wave function.
Abstract: A quantum cosmological model of the inflationary universe is investigated by solving the Wheeler-DeWitt equation. We consider a model with a minimally coupled scalar field, the potential of which is a simple double well. By applying the boundary condition of ''no boundary,'' we calculate the wave function of our model universe. We find that in a certain parameter range a big peak is formed near the maximum of the double-well potential of the scalar field, accompanied by a recession of the exponential behavior of the wave function. We show that this peak can be consistently interpreted as representing a high density of classical paths of generalized oscillating universes, and as a consequence of the constructive interference of quantum states corresponding to these classical paths by the WKB approximation. The cosmological scenario with nonvanishing, nearly critical ''velocity'' of the vacuum expectation value in the early universe, which is suggested by the behavior of the wave function, is discussed.
TL;DR: In this paper, a model describing the physical character of the cosmological expansion of the Friedmann-Robertson-Walker closed universe is developed, and the conclusion is drawn that a hidden expansion is superposed on the generally known expansion.
Abstract: In some few steps a model describing the physical character of the cosmological expansion of the Friedmann-Robertson-Walker closed universe is developed. Due to the fact that the rate of the cosmic time is changing, the conclusion is drawn that a hidden expansion is superposed on the generally known expansion of the Universe. The resulting picture-the bi-expansive model-is brought into connection with the voids in the Universe.
TL;DR: In this paper, expanding universe solutions for the Yang-Mills-Higgs system when coupled to the Poincare gauge theory of gravitation were found for the Wu-Yang-t' Hooft-Julia-Zee configurations.
Abstract: The authors found expanding Universe solutions for the Yang-Mills-Higgs system when it is coupled to the Poincare gauge theory of gravitation The Yang-Mills fields are of the Wu-Yang-t' Hooft-Julia-Zee configurations The torsion components for the spacetime are either constant, increasing, or oscillatory, depending on the nature of metric of the Universe
TL;DR: In this paper, the problem of thermalization in the very early universe is discussed by taking account of interactions among Grand Unified Theoriy (GUT) particles and torsion particles which are expected in a class of extended theory of gravity.
Abstract: Problem of thermalization in the very early universe is discussed by taking account of interactions among Grand Unified Theoriy (GUT) particles and torsion particles which are expected in a class of extended theory of gravity. It is shown that four thermal histories of the very early universe are possible, depending on the values of the coupling constant and the mass of torsion particles. Among them, there is a history in which GUT particles are thermalized for 1017-16GeV~ T~1014GeV by torsion particles.
TL;DR: In this article, the problem of the missing matter in the universe is reviewed and discussed in terms of massive neutrinos and the primordial abundances of light elements produced during the big bang nucleosynthesis can be used to determine firm bounds on the number of neutrino flavors and on the ratio of baryon to photon densities in the Universe.
Abstract: The problem of the missing matter in the Universe is reviewed and discussed in terms of massive neutrinos. The primordial abundances of light elements produced during the big bang nucleosynthesis can be used to determine firm bounds on the number of neutrino flavours and on the ratio of baryon to photon densities in the Universe. These limits imply that nonbaryonic matter is the dominant constituent of large-scale cosmic structures, being massive neutrinos the best guess for such a matter. In order that the Universe be closed, a value of the neutrino rest mass is derived, which agrees with the bounds obtained from the dynamics of galaxies and clusters of galaxies. It is also shown that density perturbations can hardly grow in a nucleon-dominated Universe, and massive neutrinos may be the seed for nucleon condensations. All these astrophysical and cosmological considerations suggest a lower and an upper bound of the neutrino rest mass.
TL;DR: For a universe of the compact Robertson-Walker cosmology, Gauss's law requires the QCD vacuum angle θ to vanish, taking with it the strongCP problem as mentioned in this paper.
Abstract: For a universe of the compact Robertson-Walker cosmology, Gauss's law requires the QCD vacuum angle θ to vanish, taking with it the strongCP problem.
Journal Article•
TL;DR: In this paper, it was shown that an inflationary fluctuation in the early universe is a mole's hole (this is possible in either a closed or open universe) or the fluctuation occupies more than half of a closed universe.
Abstract: Either an inflationary fluctuation in the early universe is a mole's hole (this is possible in either a closed or open universe) or the fluctuation occupies more than half of a closed universe. Other possibilities are extremely exotic.
29 Mar 1985
TL;DR: In this article, what is known and believed about the very early universe that period between the supposed big bang and 10 to the -37th s later -is reported, including the Planck time, quantum gravity, the SU(5) model GUT, Guth's inflationary model of the universe and quantum cosmology leading to a nonsingular universe.
Abstract: What is known and believed about the very early universe that period between the supposed big bang and 10 to the -37th s later - is reported. Particle physicists of the early 1970s, who had looked on cosmology as a somewhat dubious part of physics, realized that the very early universe offered the only scenario for testing the authenticity of their grand unified theories (GUTs) and the more esoteric ideas about SUSY or supersymmetry. Topics discussed include: the Planck time (10 to the -44th s), quantum gravity, the SU(5) model GUT, Guth's inflationary model of the universe, and quantum cosmology leading to a nonsingular universe with such features of the steady-state theory as no beginning and no end (though perhaps periods of extreme density when quantum rules held sway).
TL;DR: The theory of evolution of the universe is based upon a principle which intends to describe the distribution of matter in the universe and its metrical properties by means of a unique field φ(x).
Abstract: The theory of evolution of the Universe which we intend to propose in the present paper is based upon a principle which intends to describe the distribution of matter in the Universe and its metrical properties by means of a unique field φ(x). Let us sketch how we intend to realize this.
TL;DR: In this paper, a complete analytic description of the geodesics in the Einstein-Straus universe is given in the Newtonian approximation, and the capture of collisionless particles is discussed as a mechanism for the formation of bound systems in an expanding universe.
Abstract: A complete analytic description is given in the Newtonian approximation for the geodesics in the Einstein-Straus universe. The capture of collisionless particles is discussed as a mechanism for the formation of bound systems in an expanding universe. Relations for the change of momentum with expansion parameter of the equations of motion for free particles are recovered.
TL;DR: In this paper, the authors discussed the possibility of inhomogeneity forming during the stage of Jeans clustering in a two-component universe, so long as the growth and decay time-scales of gravitational perturbation satisfy a certain relation.
TL;DR: Using the extented Jaynes's principle of maximum entropy, this article determined the effect of the quantum phenomena on the thermodynamical properties of matter in the early stage of Universe and showed that the thermodynamic free energy of the matter of the early Universe becomes very large value due to these quantum phenomena.
Abstract: Using the extented Jaynes's principle of maximum entropy we determine the effect of the quantum phenomena on the thermodynamical properties of matter in the early stage of Universe. It is shown that the thermodynamical free energy of the matter of the early Universe becomes very large value due to these quantum phenomena. Both the entropy as well as the free energy of the Universe become singular at the Big Bang.