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Showing papers on "Particle horizon published in 1985"


Journal ArticleDOI
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


Journal ArticleDOI
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


Journal ArticleDOI
TL;DR: It is shown that the cosmological model based on this solution satisfies all the observational tests and thus is a viable alternative to the standard big-bang model.
Abstract: A solution of Einstein's equations which admits radiation and a negative-energy massless scalar creation field as a source is presented. It is shown that the cosmological model based on this solution satisfies all the observational tests and thus is a viable alternative to the standard big-bang model. The present model is free from singularity and particle horizon and provides a natural explanation for the flatness problem. We argue that these features make the creation-field cosmological model theoretically superior to the big-bang model.

61 citations


Journal ArticleDOI
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


Journal ArticleDOI
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


Journal ArticleDOI
TL;DR: In this article, a method is presented for computing the mass distribution that develops in a model universe with no characteristic lengths provided by the matter or by the background expanding cosmological model.
Abstract: A method is presented for computing the mass distribution that develops in a model universe with no characteristic lengths provided by the matter or by the background expanding cosmological model. This problem is of interest as a possible approximation to our universe and as a test of our ability to compute the evolution of the mass distribution in an expanding universe. A preliminary application of the method yields results intermediate between what has been obtained from conventional N-body models and what followed from the Davis-Peebles (1983) integration of the BBGKY hierarchy: the mass autocorrelation function xi(r) approaches the expected power-law behavior at small lag r, but xi(r) breaks below the power law at a value of xi larger than that suggested by the galaxy clustering data. 27 references.

25 citations


Journal ArticleDOI
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


Journal ArticleDOI
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.

5 citations


Journal ArticleDOI
Pavel Voráček1
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.

4 citations



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.

Journal ArticleDOI
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.

Journal ArticleDOI
TL;DR: In this paper, a possible scheme of the evolution of the universe was analyzed by studying the bound state energy spectrum in conformal gravity and investigating transitions involving spontaneous changes of the cosmological constant via excitation followed by deexcitation involving particle creation.

Journal ArticleDOI
TL;DR: In this paper, it is shown that the flatness problem admits a trivial solution if there is a boundary beyond the present particle horizon, which is the boundary beyond which the Friedmannian metric can be used.
Abstract: The chaotic initial universe seems to be less natural than the homogeneous one. Therefore, it is proposed to use the local Friedmannian metric at once in inflation scenario. It is also shown that ‘the flatness problem’ admits of a trivial solution, if there is a boundary beyond the present particle horizon.