Showing papers on "Big Rip published in 1979"
TL;DR: The general conclusion of the analysis is that an open universe need not evolve into a state of permanent quiescence and life and communication can continue for ever, utilizing a finite store of energy, if the assumed scaling laws are valid.
Abstract: Quantitative estimates are derived for three classes of phenomena that may occur in an open cosmological model of Friedmann type. (1) Normal physical processes taking place with very long time-scales. (2) Biological processes that will result if life adapts itself to low ambient temperatures according to a postulated scaling law. (3) Communication by radio between life forms existing in different parts of the universe. The general conclusion of the analysis is that an open universe need not evolve into a state of permanent quiescence. Life and communication can continue for ever, utilizing a finite store of energy, if the assumed scaling laws are valid.
272 citations
TL;DR: In this paper, the growth and subsequent collapse of homogeneous ellipsoidal perturbations in a uniform expanding background is considered as a simple model for the formation of large-scale aspherical structures in the observed universe.
Abstract: The growth and subsequent collapse of homogeneous ellipsoidal perturbations in a uniform expanding background is considered as a simple model for the formation of large-scale aspherical structures in the observed universe. Numerical calculations of the evolution of such perturbations turn out to be well described by an approximate analytic solution of the equations of motion, and simple relationships are found between the initial shape of a perturbation and its shape and kinematic properties at the time of collapse. Perturbations do not change their shape significantly until they reach a density contrast of order unity. As a result, structures with the kinematic properties of the Local Supercluster should form much more commonly in a low-density universe than in a flat universe. The homogeneity of the local Hubble flow, the motion of the Milky Way with respect to the microwave background, and the flattening of the Local Supercluster can be successfully accounted for by these models, provided that the initial perturbation is sufficiently flattened. Viable models are obtained only if the ratio of the lengths of the two smaller axes of the initial perturbation is at least 3:1 in an Einstein-de Sitter universe or at least 1.8:1 in a universe for which the density parameter (Omega) is of order 0.1, when the protocluster pancakes.
112 citations
TL;DR: In this article, the model of a homogeneous isotropic universe is studied in the presence of gauge fields, noninteracting dust, and two extra compact dimensions, and it is found that the singular "big bang" type solution can be rejected because of the drastic growth of the radius of the universe.
Abstract: The model of a homogeneous isotropic universe is studied in the presence of gauge fields, noninteracting dust, and two extra compact dimensions. It is found that the singular “big bang” type solution can be rejected because of the drastic growth of the radius of the universe. On the other hand, solutions without singularity can be found showing a very rapid oscillation (Planck frequency) with small amplitude around the data prescribing the present status of the universe.
63 citations
TL;DR: The origin of the universe as a quantum phenomenon leads to a self-consistently generated space-time structure in which the mass of the created particles is O (kappa/sup -1/2) as discussed by the authors.
Abstract: The origin of the universe as a quantum phenomenon leads to a self-consistently generated space-time structure in which the mass of the created particles is O (kappa/sup -1/2/). We interpret the origin of the universe as a phase transition in which the grand unified symmetry is spontaneously broken.
60 citations
TL;DR: In this paper, a general-relativistic model of cosmological expansion dominated by a charged background has been calculated, and is consistent with present observational limits on the Hubble constant, the deceleration parameter, and the age of the universe.
Abstract: The Proca generalization of electrodynamics admits the possibility that the universe could possess a net electric charge uniformly distributed throughout space, while possessing no electric field. A general-relativistic model of cosmological expansion dominated by such a charged background has been calculated, and is consistent with present observational limits on the Hubble constant, the deceleration parameter, and the age of the universe. However, if this cosmology applied at the present epoch, the very early expansion of the universe would have been too rapid for cosmological nucleosynthesis or thermalization of the background radiation to have occurred. Hence, domination of the present expansion by background charge appears to be incompatible with the 3-K background and big-bang production of light elements. If the present background charge density were sufficiently small (but not strictly zero), expansion from the epoch of nucleosynthesis would proceed according to the conventional scenario, but the energy due to the background charge would have dominated at some earlier epoch. This last possibility leads to equality of pressure and energy density in the primordial universe.
22 citations
TL;DR: In this paper, it is argued that in the absence of this fiducial the photonJbaryon ratio is not a 'footprint' of the initial conditions, and therefore the initial singularity could well have been highly irregular as Misner suggested.
Abstract: It is generally believed that the Universe began from a hot big bang. Among the clues to its very early history are the present day observations that the Universe is isotropic and homogeneous (as shown by the 3 K microwave background1 and galaxy counts2,3) and that there are about 109±1 photons per baryon4. Penrose and others5,6 argue that these two observations imply that the Universe was initially very nearly isotropic and homogeneous. Their arguments rely on absolute baryon conservation so that the baryon number of the Universe can be used as a fiducial to which the number of photons can be compared. In recently proposed grand unified theories of particle interactions, baryon number is not absolutely conserved7,8 and thus the baryon number of the Universe is no longer a constant. It is argued here that in the absence of this fiducial the photonJbaryon ratio is not a ‘footprint’ of the initial conditions, and therefore the initial singularity could well have been highly irregular as Misner suggested9.
10 citations
TL;DR: In this article, the authors discuss lepton number-violating processes, both in grand unified theories, and arising from black-hole production and decay in the early universe, and show that the universe has an excess of electron neutrinos comparable to the number of photons.
Abstract: If the universe has an excess of electron neutrinos comparable to the number of photons, then the cosmological helium abundance does not restrict the number of neutrino types significantly. We discuss lepton-number-violating processes, both in grand unified theories, and arising from black-hole production and decay in the early universe.
7 citations
6 citations
TL;DR: In this article, the authors describe the long-term future of the universe on the basis of the current "standard models" of cosmology, and present a review of the existing cosmology models.
TL;DR: A model Universe in which a prolonged creative act maintains the course of the traces of the Universe creation from the beginning of the world up to the present time is proposed, which allows the continuous increase of masses of all bodies present in the Universe.
Abstract: In this paper we propose a model Universe in which a prolonged creative act maintains the course of the traces of the Universe creation from the beginning of the world up to the present time. Consequently, we allow the continuous increase of masses of all bodies present in the Universe. Equations describing our model are written in terms of concepts which are developed in the previous paper (Selak, 1978) where we suggested that relevand cosmological reality has repercussions on the formulation of basic physical laws in our surroundings.
TL;DR: In this article, the primordial black hole (PBH) hypothesis was proposed to reconcile the assumption of initial symmetry with the observed asymmetry, and it was shown that PBHs are ideal stores for antimatter.
Abstract: Undoubtedly complete symmetry of charge in the initial state of the Universe is an attractive idea. However, analysis of observational data1 indicates that the visible Universe contains mostly particles of positive baryon number. Attempts2–6 to reconcile the assumption of initial symmetry with this observed asymmetry have met with some difficulties. However, if one accepts that the Universe is symmetric in baryon charge, then there must be regions of space or objects which contain at least as much antimatter as the matter which we observe. We propose here that the hypothesis of primordial black holes (PBHs)7,8 offers a simple and economic solution of the problem. Because of the well-known ‘no hair’ theorems the baryonic charge of PBHs cannot be observed, and hence PBHs are ideal stores for antimatter.