共查询到20条相似文献,搜索用时 125 毫秒
1.
V. U. M. Rao M. Vijaya Santhi T. Vinutha G. Sree?Devi?Kumari 《International Journal of Theoretical Physics》2012,51(10):3303-3310
Bianchi type-I dark energy model with variable equation of state (EoS) parameter is presented in a scalar-tensor theory of gravitation proposed by Brans and Dicke (Phys. Rev. 124:925, 1961). To get a determinate solution of the field equations we will take the help of special law of variation for Hubble’s parameter presented by Bermann (Nuovo Cimento B. 74:182, 1983) which yields a dark energy cosmological model with negative constant deceleration parameter. It is observed that this dark energy cosmological model always represents an accelerated and expanding universe and also consistent with the recent observations of type-Ia supernovae. Some physical and geometrical properties of the model are also discussed. 相似文献
2.
D. R. K. Reddy P. Govinda Rao R. L. Naidu 《International Journal of Theoretical Physics》2008,47(12):3150-3155
Five dimensional Kaluza-Klein Space-time is considered in the presence of thick domain walls in the scalar-tensor theory formulated
by Brans and Dicke (Phys. Rev. 124:925, 1961). Exact cosmological model, in this theory, is presented with the help of special law of variation proposed by Berman (Nuovo
Cim. B 74:182, 1983) for Hubble’s parameter. Some physical and kinematical properties of the model are also discussed. 相似文献
3.
K. S. Adhav A. S. Nimkar M. R. Ugale M. V. Dawande 《International Journal of Theoretical Physics》2008,47(3):634-639
Bianchi type-III space time is considered in the presence of perfect fluid source in the scalar-tensor theory of gravitation
proposed by Brans and Dicke (Phys. Rev. 124:925, 1961). With the help of special law of variation for Hubble’s parameter proposed by Bermann (Nuovo Cimento 74B:182, 1983) a cosmological model with negative constant deceleration parameter is obtained in the presence of perfect fluid with disordered
radiation. Some physical and kinematical properties of the model are also discussed. 相似文献
4.
S. D. Katore R. S. Rane K. S. Wankhade 《International Journal of Theoretical Physics》2010,49(1):187-193
We have studied the evolution of spatially homogeneous and isotropic FRW cosmological model with bulk-viscosity in the frame
work of Barber’s (Gen. Relativ. Gravit. 14: 117, 1982) second self-creation theory of gravitation. The cosmological models are obtained with the help of special law of variation
for Hubble parameter proposed by Bermann (Nuovo Cimento 74B: 182, 1983). Physical parameters of the models have been discussed in case of false vacuum model, Zel’dovich fluid and radiation dominated
fluid. 相似文献
5.
In this paper, we have investigated spatially homogeneous isotropic Friedman-Robertson-Walker cosmological model with bulk viscosity and zero-mass scalar field in the frame work of Barber’s second self-creation theory (Gen. Relativ. Gravit. 14:117, 1982). The cosmological models are obtained with the help of the special law of variation for Hubble’s parameter proposed by Bermann (Nuovo Cimento B 74:182, 1983) and power law relation. Some physical properties of the models are also discussed. 相似文献
6.
Spatially homogeneous and anisotropic LRS Bianchi type-I metric is considered in the framework of Nordtvedt-Barker’s general
scalar-tensor theory of gravitation when the source for the energy momentum tensor is a perfect fluid. With the help of a
special law of variation for Hubble’s parameter proposed by Berman (Nuovo Cim. B. 74:182, 1983) a cosmological model with negative constant deceleration parameter is obtained. Some physical and kinematical properties
of the model are also discussed. 相似文献
7.
We have investigated cosmological model with strange quark matter attached to the string cloud in general theory of gravitation
for Axially Symmetric space time. The model is obtained with the help of special law of variation for Hubble parameter proposed
by Bermann (Nuovo Cimento B 74:182, 1983). Also, some physical and kinematics properties of the model are discussed. 相似文献
8.
R. L. Naidu B. Satyanarayana D. R. K. Reddy 《International Journal of Theoretical Physics》2012,51(7):1997-2002
A spatially homogeneous and anisotropic Bianchi type-V universe with variable equation of state (EoS) parameter and constant deceleration parameter is obtained in a scalar-tensor theory of gravitation proposed by Saez and Ballester (Phys. Lett. A 113:467, 1986). The physical and kinematical properties of the universe have been discussed. 相似文献
9.
Anirudh Pradhan H. Amirhashchi Bijan Saha 《International Journal of Theoretical Physics》2011,50(9):2923-2938
A new dark energy model in anisotropic Bianchi type-I (B-I) space-time with time dependent equation of state (EoS) parameter
and constant deceleration parameter has been investigated in the present paper. The Einstein’s field equations have been solved
by applying a variation law for generalized Hubble’s parameter (Berman in Il Nuovo Cimento B 74:182, 1983) which generates two types of solutions, one is of power-law type and other is of the exponential form. The existing range
of the dark energy EoS parameter ω for derived model is found to be in good agreement with the three recent observations (i) SNe Ia data (Knop et al. in Astrophys.
J. 598:102, 2003), (ii) SNe Ia data collaborated with CMBR anisotropy and galaxy clustering statistics (Tegmark et al. in Astrophys. J. 606:702,
2004) and (iii) a combination of cosmological datasets coming from CMB anisotropies, luminosity distances of high redshift type
Ia supernovae and galaxy clustering (Hinshaw et al. in Astrophys. J. Suppl. Ser. 180:225, 2009 and Komatsu et al. in Astrophys. J. Suppl. Ser. 180:330, 2009). The cosmological constant Λ is found to be a decreasing function of time and it approaches a small positive value at the
present epoch which is corroborated by results from recent supernovae Ia observations. It has also been suggested that the
dark energy that explains the observed accelerating universe may arise due to the contribution to the vacuum energy of the
EoS in a time dependent background. Geometric and kinematic properties of the model and the behaviour of the anisotropy of
the dark energy have been carried out. 相似文献
10.
The order-of-magnitude method proposed by Struchtrup (Phys. Fluids 16(11):3921–3934, 2004) is a new closure procedure for the infinite moment hierarchy in kinetic theory of gases, taking into account the scaling
of the moments. The scaling parameter is the Knudsen number Kn, which is the mean free path of a particle divided by the system size. 相似文献
11.
S. D. Katore 《International Journal of Theoretical Physics》2012,51(1):83-89
We have obtained FRW cosmological model with strange quark matter attached to the string cloud in general relativity. The
model is obtained with the help of special law of variation for Hubble parameter proposed by Bermann (Nuovo Cimento 74B:182,
1983). Also, some physical and kinematics properties of the model are discussed. The results are analogous to results obtained
by Yilmaz (Gen. Relativ. Gravit. 38:1397–1406, 2006). 相似文献
12.
We report on some implications of the theory of turbulence developed by V. Yakhot (Phys. Rev. E 57(2):1737, 1998). In particular we focus on the expression for the scaling exponents ζ
n
. We show that Yakhot’s result contains three well known scaling models as special cases, namely K41, K62 and the theory by
V. L’vov and I. Procaccia (Phys. Rev. E 62(6):8037, 2000). The model furthermore yields a theoretical justification for the method of extended self-similarity (ESS). 相似文献
13.
In this paper, a spatially homogeneous and anisotropic Bianchi type-I space-time filled with perfect fluid is investigated
within the framework of a scalar-tensor theory proposed by Saez and Ballester. Two different physically viable models of the
universe are obtained by using a special law of variation for Hubble’s parameter that yields a constant value of deceleration
parameter. One of the models is found to generalize a model recently investigated by Reddy et al. (Astrophys. Space Sci. 306:171,
2006). The Einstein’s field equations are solved exactly and the solutions are found to be consistent with the recent observations
of type Ia supernovae. A detailed study of physical and kinematical properties of the models is carried out. 相似文献
14.
In this paper, we investigate Bianchi type-III universe which has dynamical energy density. We introduce three different skewness parameters along spatial directions to quantify the deviation of pressure from isotropy. We also assume that the skewness parameters are time dependent. The Saez-Ballester (J. Phys. Lett. A 113:467, 1986) field equations have been solved by applying a variation law for generalized Hubble’s parameter given by Bermann (Nuovo Cimento B 74:182, 1983). Some physical and kinematical properties of dark energy model are discussed. 相似文献
15.
In experiments of games, players frequently make choices which are regarded as irrational in game theory. In papers of Khrennikov
(Information Dynamics in Cognitive, Psychological and Anomalous Phenomena. Fundamental Theories of Physics, Kluwer Academic,
Norwell, 2004; Fuzzy Sets Syst. 155:4–17, 2005; Biosystems 84:225–241, 2006; Found. Phys. 35(10):1655–1693, 2005; in QP-PQ Quantum Probability and White Noise Analysis, vol. XXIV, pp. 105–117, 2009), it was pointed out that statistics collected in such the experiments have “quantum-like” properties, which can not be explained
in classical probability theory. In this paper, we design a simple quantum-like model describing a decision-making process
in a two-players game and try to explain a mechanism of the irrational behavior of players. Finally we discuss a mathematical
frame of non-Kolmogorovian system in terms of liftings (Accardi and Ohya, in Appl. Math. Optim. 39:33–59, 1999). 相似文献
16.
K. S. Adhav A. S. Nimkar M. V. Dawande 《International Journal of Theoretical Physics》2008,47(12):3201-3206
Axially symmetric Bianchi type-I cosmological micro model is obtained in Barber’s (Gen. Relativ. Gravit. 14:117, 1982) modified theory of general relativity. Some properties of the model are discussed. 相似文献
17.
A simple model for the dynamics of the Magellanic Stream (MS), in the framework of modified gravity models is investigated.
We assume that the galaxy is made up of baryonic matter out of context of dark matter scenario. The model we used here is
named Modified Gravity (MOG) proposed by Moffat (J. Cosmol. Astropart. Phys. 003, 2005). In order to examine the compatibility of the overall properties of the MS under the MOG theory, the observational radial
velocity profile of the MS is compared with the numerical results using the χ
2 fit method. In order to obtain the best model parameters, a maximum likelihood analysis is performed. We also compare the
results of this model with the Cold Dark Matter (CDM) halo model and the other alternative gravity model that proposed by
Bekenstein (Phys. Rev. D 70:083509, 2004), so called TeVeS. We show that by selecting the appropriate values for the free parameters, the MOG theory seems to be plausible
to explain the dynamics of the MS as well as the CDM and the TeVeS models. 相似文献
18.
K. S. Adhav M. R. Ugale C. B. Kale M. P. Bhende 《International Journal of Theoretical Physics》2007,46(12):3122-3127
An exact Bianchi type-VI string cosmological model is obtained in a scalar-tensor theory of gravitation proposed by Saez and
Ballester (Phys. Lett. 113:467, 1985). Some physical properties of the model are also discussed. 相似文献
19.
The paper deals with an anisotropic Bianchi type VIo cosmological model with variable ω in the presence and absence of magnetic field of energy density ρ
B
. A special law of variation for Hubble’s parameter proposed by Berman (Nuovo Cimento B 74:182, 1983) has been utilized to solve the field equations. 相似文献
20.
Anatoliy K. Prykarpatsky Nikolai N. Bogolubov 《International Journal of Theoretical Physics》2012,51(1):237-245
R. Feynman’s “heretical” approach (Dyson in Am. J. Phys. 58:209–211, 1990; Dyson in Phys. Today 42(2):32–38, 1989) to deriving the Lorentz force based Maxwell electromagnetic equations is revisited, the its complete legacy is argued both
by means of the geometric considerations and its deep relation with the vacuum field theory approach devised (Prykarpatsky
et al. in Int. J. Theor. Phys. 49:798–820, 2010; Prykarpatsky et al. in Preprint ICTP, 2008, ). Being completely classical, we reanalyze the Feynman’s derivation from the classical Lagrangian and Hamiltonian points
of view and construct its nontrivial relativistic generalization compatible with the vacuum field theory approach. 相似文献