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The time-asymmetry of the universe is essentially produced by its low-entropy, unstable states. Using quantitative arguments Paul Davies has demonstrated that the expansion of the universe coupled with nuclear reaction within the stars may produce a decrease in entropy, thereby explaining its low entropy states. This idea is implemented in a qualitative way in a simple homogeneous model. Some rough coincidence with observational data is found. 相似文献
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V. S. Troitskii 《Astrophysics and Space Science》1993,201(2):203-221
It is known that the correlation between the observed visible luminositym(z), angular dimension (z) of galaxies on the red shiftz and theoretical relations of the standard cosmology is possible only under the assumption that the luminosity and object dimension evolution are equal toL(z) =L
0(z + 1)3.2 andl(z) =l
0(z + 1)–2, respectively. This evolution is hypothetical, since it is defined by a theory which is not confirmed by experience. In order to solve the problem on the reality of the Universe expansion, it is sufficient to prove or disprove these conclusions using methods of measurement independent of the theory. One of these methods consists of defining the dependence of the radiation spectra of galaxies and quasars onz which evidently is proportional to the spectrum of absolute luminosityL(, z). It has subsequently been shown that the spectrum form is practically independent of the red shift - i.e., it remains constant during the lifetime of galaxies and quasars. Consequently, to explain the luminosity increase required by the standard cosmology, it is necessary to admit a completely unreal entity (at all wavelengths of the optical spectrum increase) of the radiation spectral density of (z + 1)3.2 times. We can conclude that in reality the luminosity evolution is either absent or its power index is smaller at least by an order of magnitude. It is likely, therefore, that the established is the result of an inadequate standard in cosmology.Another method is the use of the observed relations between the parameters ofL andl galaxies. A number of measurements made by different authors gives the relationlL
a
, where 0.33a1.6. It then follows thatl(z)(z + 1)3.2a
. This dependence of the galaxy dimension is inverse to the dependence predicted by the standard cosmology. Besides, in order to make a correlation between thel(z)(z + 1)3.2a
and measurements of (z), it is necessary that indices of the degree of luminosity evolution should be smaller by an order of magnitude.Thus, the luminosity increase and simultaneous decrease of galaxy and quasar dimensions predicted by the standard cosmolog are not confirmed by the direct astrophysical measurements. This discrepancy is the consequence of an incorrect hypothesis of Universe expansion and the relativistic cosmology based on it. 相似文献
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This study is emphasized to explore the validity of generalized second law of thermodynamics in the context of non-linear electrodynamics (magnetic effects only) with Brans-Dicke chameleon scalar field as dark energy candidate. For this purpose, we consider FRW universe model with perfect fluid matter contents. We evaluate matter energy density and magnetic field by taking interacting and non-interacting cases of magnetic field and matter as well as the power law ansatz for scalar field. The validity of this law is discussed by using the first law of thermodynamics for four different horizons: Hubble, apparent, particle and event horizons. We conclude that this law may hold for all four horizons with small positive red-shift when chameleon mechanism is taken into account in Brans-Dicke gravity. Finally, we investigate the statefinders in order to check the viability of the model. 相似文献
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Some similarities of expansion phenomena in the vicinity of the earth and in the universe as a whole
H. A. Harutyunian 《Astrophysics》1995,38(4):374-378
Some expansion phenomena in the immediate vicinity of the Earth and their influence on the Earth's angular momentum are considered. It is noted that the tidal mechanism which is traditionally used to explain the lunar retreat is actually unfounded. These expansion effects are compared with the Hubble expansion of the universe and their similarity is shown. A way for the solution of the lunar retreat paradox is suggested combining the tidal effects and Hubble expansion. An increase of the Earth-Sun distance is predicted and the rate of this removal is estimated.Published in Astrofizika, Vol. 38, No. 4, pp. 667–674, October–December, 1995. 相似文献
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H. A. Harutyunian 《Astrophysics》2011,54(2):290-299
An attempt is made to study the concept of “black holes” from the standpoint of the axioms of modern physics. It is found
that matter which lies inside a Schwarzschild sphere must disappear, both as a source of electromagnetic waves and as a source
of a gravitational field. To resolve this paradox a hypothesis is proposed according to which the accelerated expansion of
the universe interacts with atomic nuclei in such a way as to transfer a positive energy to every nucleus in accordance with
its volume. The influx of energy into a nucleus gradually neutralizes its binding energy, so that there is an increase in
the mass of the nucleus, as well as of its component nucleons. This mechanism suggests that during the inverse process, when
matter is compressed, the opposite phenomenon should be observed with a release of binding energy, and the average mass of
the nucleons involved in this process should decrease; that is, part of the mass of the material is simply converted into
energy. 相似文献
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Hasmukh K. Tank 《Astrophysics and Space Science》2011,336(2):341-343
This letter points out that the values of ‘critical-acceleration’ of MOND, and the ‘accelerated-expansion’ of the universe
are just two of the fourteen strikingly equal values of accelerations recurring in different physical situations. Some of
them could be explained by a new law of equality of potential-energy and energy-of-mass of reasonably-independent systems
(Tank in Astrophys. Space Sci. 330:203–205, 2010; Tank in Adv. Stud. Theor. Phys. 5:45–55, 2011). This new conservation-law, of equality of potential-energy, energy-of-mass and ‘kinetic-energy’ may be a clue to understand
MOND, and the ‘accelerated-expansion’ of the universe. Alternative expressions for the cosmological red-shift, the ‘critical-acceleration’
of MOND and Newton’s law of universal gravitation are also presented for comparison of three different accelerations. 相似文献
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A. M. Anile 《Astrophysics and Space Science》1974,29(2):415-426
The relativistic transfer equation for polarised radiation is solved in an axisymmetric Bianchi type I universe. Previous
results concerning the linear polarisation induced in the cosmic microwave background radiation by Thomson scattering in an
anisotropically expanding universe are confirmed.
Work partly done at the Osservatorio Astrofisico, Catania (Italia). 相似文献
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Ahmad Rami El-Nabulsi 《Astrophysics and Space Science》2010,326(2):169-174
A modified higher-dimensional cosmology with a static traversable wormhole and dominated by a variable modified Chaplygin gas is constructed. Many interesting features are explored and discussed in some detail. 相似文献
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Antonio Alfonso-Faus 《Astrophysics and Space Science》2012,337(1):367-372
Combining the kinematical definitions of the two dimensionless parameters, the deceleration q(x) and the Hubble t
0
H(x), we get a differential equation (where x=t/t
0 is the age of the universe relative to its present value t
0). First integration gives the function H(x). The present values of the Hubble parameter H(1) [approximately t
0
H(1)≈1], and the deceleration parameter [approximately q(1)≈−0.5], determine the function H(x). A second integration gives the cosmological scale factor a(x). Differentiation of a(x) gives the speed of expansion of the universe. The evolution of the universe that results from our approach is: an initial
extremely fast exponential expansion (inflation), followed by an almost linear expansion (first decelerated, and later accelerated).
For the future, at approximately t≈3t
0 there is a final exponential expansion, a second inflation that produces a disaggregation of the universe to infinity. We
find the necessary and sufficient conditions for this disaggregation to occur. The precise value of the final age is given
only with one parameter: the present value of the deceleration parameter [q(1)≈−0.5]. This emerging picture of the history of the universe represents an important challenge, an opportunity for the
immediate research on the Universe. These conclusions have been elaborated without the use of any particular cosmological
model of the universe. 相似文献
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Màrius Josep Fullana?i?Alfonso Antonio Alfonso-Faus 《Astrophysics and Space Science》2012,337(1):19-20
It has been shown that black holes can be quantized by using Bohr’s idea of quantizing the motion of an electron inside the
atom. We apply these ideas to the universe as a whole. This approach reinforces the suggestion that it may be a way to unify
gravity with quantum theory. 相似文献
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Jayant V. Narlikar Geoffrey Burbidge R. G. Vishwakarma 《Journal of Astrophysics and Astronomy》2007,28(2-3):67-99
In this paper we discuss the properties of the quasi-steady state cosmological model (QSSC) developed in 1993 in its role
as a cyclic model of the universe driven by a negative energy scalar field. We discuss the origin of such a scalar field in
the primary creation process first described by F. Hoyle & J. V. Narlikar forty years ago. It is shown that the creation processes
which take place in the nuclei of galaxies are closely linked to the high energy and explosive phenomena, which are commonly
observed in galaxies at all redshifts.
The cyclic nature of the universe provides a natural link between the places of origin of the microwave background radiation
(arising in hydrogen burning in stars), and the origin of the lightest nuclei (H, D, He3 and He4). It also allows us to relate the large scale cyclic properties of the universe to events taking place in the nuclei of galaxies.
Observational evidence shows that ejection of matter and energy from these centers in the form of compact objects, gas and
relativistic particles is responsible for the population of quasi-stellar objects (QSOs) and gamma-ray burst sources in the
universe.
In the later parts of the paper we briefly discuss the major unsolved problems of this integrated cosmological and cosmogonical
scheme — the understanding of the origin of the intrinsic redshifts, and the periodicities in the redshift distribution of
the QSOs. 相似文献
18.
D. F. Roscoe 《Astrophysics and Space Science》1996,244(1-2):231-248
The work of this paper is based on work which has been described in a preliminary form in Roscoe (1995), and it applies the formalism developed there to the problem of deriving the cosmology for a universe which is in a state of gravitational equilibrium. It predicts that, in such a universe, material is distributed in a fractal fashion with fractal dimensiontwo whilst redshifts necessarily occur in integer multiples of a basic unit and, given a certain model for light propagation, the measured magnitudes of peculiar velocities will increase in direct proportion to cosmological redshift.The first of these predictions is strongly supported by the results of the most modern pencil-beam and wide-angle surveys, whilst the second conforms with the results of very recent rigorous analyses of accurately measured redshifts of nearby spiral galaxies and the third is in qualitative agreement with the very limited data available. The observational support for these predictions is described in detail in the text. 相似文献
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B. Novosyadlyj O. Sergijenko V. M. Shulga 《Kinematics and Physics of Celestial Bodies》2017,33(6):255-264
The formation of first molecules, negative Hydrogen ions, and molecular ions in a model of the Universe with cosmological constant and cold dark matter is studied. The cosmological recombination is described in the framework of modified model of the effective 3-level atom, while the kinetics of chemical reactions is described in the framework of the minimal model for Hydrogen, Deuterium, and Helium. It is found that the uncertainties of molecular abundances caused by the inaccuracies of computation of cosmological recombination are approximately 2–3%. The uncertainties of values of cosmological parameters affect the abundances of molecules, negative Hydrogen ions, and molecular ions at the level of up to 2%. In the absence of cosmological reionization at redshift z = 10, the ratios of abundances to the Hydrogen one are 3.08 × 10–13 for H–, 2.37 × 10–6 for H2, 1.26 × 10–13 for H2+, 1.12 × 10–9 for HD, and 8.54 × 10–14 for HeH+. 相似文献
20.
A. Mészáros 《Astrophysics and Space Science》1993,207(1):5-15
In the paper the void is modeled as a spherical underdense region surrounded by shells changing into the Friedmannian exterior. This model is in fact a single Tolman-Bondi metric, where at the edge of the void the density need not be continuous. In principle, there may exist 72 variations. These models contain also the cases, when in the void itself there is a Minkowskian vacuum; the shell crossing is not excluded, too. Some technical results are obtained for the Tolman-Bondi metric. Using them, the questions of stability and other theoretical problems are investigated. Some observational facts concerning the voids are also used. As the key result a truncation of the possible models is obtained; only 14 models are physically reasonable. This means that the universe is either hyperbolically expanding (this possibility strengthens the proposition of Bonnor and Chamorro, (1990); (1991)), or there is a shell crossing. Thus the discovery of voids is an observational support either for the open universe or for the shell crossing scenario of galaxy formation (Mészáros, 1991), where no anisotropy of microwave background radiation is needed in a baryon dominated universe. 相似文献