共查询到20条相似文献,搜索用时 31 毫秒
1.
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
2.
D. R. K. Reddy R. L. Naidu B. Satyanarayana 《International Journal of Theoretical Physics》2012,51(10):3222-3227
A five dimensional Kaluza-Klein space-time is considered in the presence of perfect fluid source in f(R,T) gravity proposed by Harko et al. ( [gr-qc], 2011). A cosmological model with a negative constant deceleration parameter with an appropriate choice of a function f(T) is presented. To find a determinate solution of the field equations it is assumed that scalar of expansion is proportional to the shear scalar of the space time. The physical behavior of the model is also studied. 相似文献
3.
P. K. Sahoo 《International Journal of Theoretical Physics》2008,47(11):3029-3034
Spherically symmetric space-time is considered in bimetric theory of gravitation formulated by Rosen (Gen. Relativ. Gravit.
4:435, [1973]) in the presence of perfect fluid, massive scalar field and cosmic string. It is shown that either macro cosmological model
represented by perfect fluid or cosmic string do not exist and only a vacuum model can be constructed whereas in case of a
micro cosmological model represented by a scalar field exists and the model is obtained. 相似文献
4.
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
5.
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
6.
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
7.
Field equations of Wesson’s (Wesson in Mon. Not. R. Astron. Soc. 197:157, 1981) scale invariant theory are obtained, with the aid of a plane symmetric metric in the presence of perfect fluid distribution.
Model corresponding to stiff fluid is constructed and discussed. It is found that the model admits a big bang like singularity
at initial epoch. Moreover, the shape of the universe remains unchanged during evolution. 相似文献
8.
P. K. Sahoo 《International Journal of Theoretical Physics》2009,48(7):2022-2026
It is shown that the inhomogeneous plane symmetric perfect fluid distribution and cosmic strings do not survive in frame work
of bimetric theory of gravitation proposed by Rosen (Gen. Relativ. Gravit. 4:435, 1973). Hence vacuum models are presented and studied. 相似文献
9.
10.
D. R. K. Reddy R. L. Naidu B. Satyanarayana 《International Journal of Theoretical Physics》2012,51(10):3045-3051
An axially symmetric Bianchi type-I space time with variable equation of state (EoS) parameter and constant deceleration parameter has been investigated in scale covariant theory of gravitation formulated by Canuto et al. (Phys. Rev. Lett. 39:429, 1977). With the help of special law of variation for Hubble’s parameter proposed by Bermann (Nuovo Cimento 74B:182, 1983) a dark energy cosmological model is obtained in this theory. Some physical and kinematical properties of the model are also discussed. 相似文献
11.
D. R. K. Reddy 《International Journal of Theoretical Physics》2009,48(11):3044-3048
Kaluza-Klein space-time is considered in the presence of a perfect fluid distribution in the scale-covariant theory of gravitation by Canuto et al. (Phys. Rev. Lett. 39:429, 1977). With the help of special law of variation for Hubble’s parameter proposed by Bermann (Nuovo Cimento 74B:182, 1983), a cosmological model in five dimensions with a negative constant deceleration parameter is presented in this theory. Some physical and kinematical properties of the model are also discussed. 相似文献
12.
D. R. K. Reddy R. Santhi Kumar T. V. Pradeep Kumar 《International Journal of Theoretical Physics》2013,52(1):239-245
A dark energy model with EoS parameter is investigated in f(R,T) gravity in Bianchi type-III space-time in the presence of perfect fluid source. To obtain a determinate solution special law of variation for Hubble’s parameter proposed by Berman (Nuovo Cimento B 74:183, 1983) is used. We have also assumed that the scalar expansion is proportional to shear and the EoS parameter is proportional to skewness parameter. It is observed that the EoS parameter, skewness parameters in the model turn out to be functions of cosmic time. Some physical and kinematical properties of the model are also discussed. 相似文献
13.
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
14.
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
15.
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
16.
S. D. Katore R. S. Rane K. S. Wankhade 《International Journal of Theoretical Physics》2010,49(9):2105-2112
In this paper, we have obtained the solutions of perfect fluid cosmological model in Cylindrically-symmetric space time (Marder
in Proc. R. Soc. A 246:133, 1958) with varying cosmological constant in the presence of electromagnetic field. To get determinate model of the universe we
assumed that the scalar of expansion in the model is proportional to the eigen-value of the shear tensor which lead to the
condition A=(BC)
n
. The magnetic field is due to an electric current produced along x-axis. Thus the magnetic field is in yz-plane and F
23 is the only non-vanishing component of electromagnetic field tensor F
ij
. Various physical and geometrical features of the model have been discussed. 相似文献
17.
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
18.
Prateek Jain Pradyumn Kumar Sahoo Bivudutta Mishra 《International Journal of Theoretical Physics》2012,51(8):2546-2551
The purpose of this paper is to investigate the role of wet dark fluid in axially symmetric cosmological model within the frame work of bimetric theory of gravitation proposed by Rosen (Gen. Relativ. Gravit. 4:435, 1973). In this theory, it is observed that there is no contribution from wet dark fluid. 相似文献
19.
The spatially homogeneous and totally anisotropic Bianchi Type-II space-time dark energy model with EoS parameter is considered in the presence of a perfect fluid source in the framework of f(R,T) gravity proposed by Harko et al. (Phys. Rev. D, 84:024020, 2011). With the help of special law of variation for Hubble’s parameter proposed by Berman (Nuovo Cimento B, 74:182, 1983) a dark energy cosmological model is obtained in this theory. We consider f(R,T) model and investigate the modification R+f(T) in Bianchi type-II cosmology with an appropriate choice of a function f(T)=λT. We use the power law relation between average Hubble parameter H and average scale factor R to find the solution. The assumption of constant deceleration parameter leads to two models of universe, i.e. power law model and exponential model. Some physical and kinematical properties of the model are also discussed. 相似文献
20.
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