共查询到20条相似文献,搜索用时 31 毫秒
1.
Rahul Ghosh Surajit Chattopadhyay Ujjal Debnath 《International Journal of Theoretical Physics》2012,51(2):589-603
This work is motivated by the work of Kim et al. (Mod. Phys. Lett. A 23:3049, 2008), which considered the equation of state parameter for the new agegraphic dark energy based on generalized uncertainty principle
coexisting with dark matter without interaction. In this work, we have considered the same dark energy interacting with dark
matter in emergent, intermediate and logamediate scenarios of the universe. Also, we have investigated the statefinder, kerk and lerk parameters in all three scenarios under
this interaction. The energy density and pressure for the new agegraphic dark energy based on generalized uncertainty principle
have been calculated and their behaviors have been investigated. The evolution of the equation of state parameter has been
analyzed in the interacting and non-interacting situations in all the three scenarios. The graphical analysis shows that the
dark energy behaves like quintessence era for logamediate expansion and phantom era for emergent and intermediate expansions
of the universe. 相似文献
2.
Jibitesh Dutta Subenoy Chakraborty 《International Journal of Theoretical Physics》2011,50(8):2383-2390
In this paper, we investigate the validity of the generalized second law of thermodynamics (GSLT) in the DGP braneworld when the universe is filled with interacting two fluid system: one in the form of cold dark matter and other is holographic dark energy. The boundary of the universe is assumed to be enclosed by the dynamical apparent horizon or the event horizon. The universe is chosen to be homogeneous and isotropic FRW model and the validity of the first law has been assumed here. 相似文献
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We consider the new agegraphic model of dark energy with a varying gravitational constant, G, in a non-flat universe. We obtain the equation of state and the deceleration parameters for both interacting and noninteracting
new agegraphic dark energy. We also present the equation of motion determining the evolution behavior of the dark energy density
with a time variable gravitational constant. Finally, we generalize our study to the case of viscous new agegraphic dark energy
in the presence of an interaction term between both dark components. 相似文献
6.
M. Umar Farooq Mubasher Jamil Muneer A. Rashid 《International Journal of Theoretical Physics》2010,49(9):2278-2287
We consider the new agegraphic dark energy model with the help of the quantum corrections to the entropy-area relation in
the setup of loop quantum gravity. Employing this new form of dark energy so called entropy-corrected new agegraphic dark
energy (ECNADE), we investigate the model of interacting dark energy and derive its equation of state (EoS). We study the
correspondence between the K-essence, tachyon and dilaton scalar fields with the interacting (ECNADE)in the non-flat FRW universe.
Moreover, we reconstruct the corresponding scalar potentials which describe the dynamics of the scalar field. 相似文献
7.
Ujjal Debnath Surajit Chattopadhyay 《International Journal of Theoretical Physics》2013,52(4):1250-1264
In this work, we have considered that the flat FRW universe is filled with the mixture of dark matter and the new holographic dark energy. If there is an interaction, we have investigated the natures of deceleration parameter, statefinder and Om diagnostics. We have examined the validity of the first and generalized second laws of thermodynamics under these interactions on the event as well as apparent horizon. It has been observed that the first law is violated on the event horizon. However, the generalized second law is valid throughout the evolution of the universe enveloped by the apparent horizon. When the event horizon is considered as the enveloping horizon, the generalized second law is found to break down excepting at late stage of the universe. 相似文献
8.
In this paper, we investigate the new agegraphic dark energy model in the framework of Brans-Dicke theory, which is a natural extension of the Einstein's general relativity. In this framework the form of the new agegraphic dark energy density takes as ρq =3n2 φ(t) η-2, where η is the conformalage of the universe and φ(t) is the Brans-Dicke scalar field representing the inverse of the time-variable Newton's constant. We derive the equation of state of the new agegraphic dark energy and the deceleration parameter of the universe in the Brans-Dicke theory. It is very interesting to find that in the Brans-Dicke theory the agegraphic dark energy realizes quintom-like behavior,i.e., its equation of state crosses the phantom divide w=-1 duringthe evolution. We also compare the situation of the agegraphic darkenergy model in the Brans-Dicke theory with that in the Einstein'stheory. In addition, we discuss the new agegraphic dark energy modelwith interaction in the framework of the Brans-Dicke theory. 相似文献
9.
Antonio Pasqua Surajit Chattopadhyay Iuliia Khomenko 《International Journal of Theoretical Physics》2013,52(7):2496-2507
The new agegraphic Dark Energy (NADE) model (based on generalized uncertainty principle) interacting with Dark Matter (DM) is considered in this study via power-law form of the scale factor a(t). The equation of state (EoS) parameter ω G is observed to have a phantom-like behaviour. The stability of this model is investigated through the squared speed of sound $v_{s}^{2}$ . It is found that $v_{s}^{2}$ always stays at negative level. This indicates instability of the considered model. Moreover, validity of the generalized second law of thermodynamics has been investigated assuming that the apparent horizon is the enveloping horizon. It has been observed that the generalized second law is valid throughout the evolution of the universe. 相似文献
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Motivated by a recent work of one of us (Sheykhi in Phys Rev D 81: 023525, 2010), we extend it by using quantum (or entropy)
corrected new agegraphic dark energy in the Brans–Dicke cosmology. The correction terms are motivated from the loop quantum
gravity which is one of the competitive theories of quantum gravity. Taking the non-flat background spacetime along with the
conformal age of the universe as the length scale, we derive the dynamical equation of state of dark energy and the deceleration
parameter. An important consequence of this study is the phantom divide scenario with entropy-corrected new agegraphic dark
energy. Moreover, we assume a system of dark matter, radiation and dark energy, while the later interacts only with dark matter.
We obtain some essential expressions related with dark energy dynamics. The cosmic coincidence problem is also resolved in
our model. 相似文献
11.
Rong-Jia Yang Jing-Zhao Qi Lihua Feng 《International Journal of Theoretical Physics》2012,51(6):1692-1697
Assuming that the equation of state of dark energy is a constant, we obtain the allowed interval of the equation of state
of dark energy: w
D≥−1, bounded from the generalized second law of thermodynamics, in a universe enveloped by the apparent horizon and containing
a Schwarzschild black hole. 相似文献
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The purpose of this paper is to discuss the evolution of modified holographic dark energy with variable G in non-flat Kaluza–Klein universe. We consider the non-interacting and interacting scenarios of the modified holographic
dark energy with dark matter and obtain the equation of state parameter through logarithmic approach. It turns out that the
universe remains in different dark energy eras for both cases. Further, we study the validity of the generalized second law
of thermodynamics in this scenario. We also justify that the statefinder parameters satisfy the limit of ΛCDM model. 相似文献
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Nairwita Mazumder Subenoy Chakraborty 《International Journal of Theoretical Physics》2012,51(1):124-132
Here we are trying to find the conditions for the validity of the generalized second law of thermodynamics (GSLT) assuming
the first law of thermodynamics on the event horizon in both cases when the FRW universe is filled with interacting two fluid
system- one in the form of cold dark matter and the other is either holographic dark energy or new age graphic dark energy. 相似文献
16.
In this work we consider the entropy-corrected version of interacting holographic dark energy (HDE), in the non-flat universe
enclosed by apparent horizon. Two corrections of entropy so-called logarithmic ‘LEC’ and power-law ‘PLEC’ in HDE model with
apparent horizon as an IR-cutoff are studied. The ratio of dark matter to dark energy densities u, equation of state parameter w
D
and deceleration parameter q are obtained. We show that the cosmic coincidence problem is solved for interacting models. By studying the effect of interaction
in EoS parameter of both models, we see that the phantom divide may be crossed and also understand that the interacting models
can drive an acceleration expansion at the present and future, while in non-interacting case, this expansion can happen only
at the early time. The graphs of deceleration parameter for interacting models, show that the present acceleration expansion
is preceded by a sufficiently long period deceleration at past. Moreover, the thermodynamical interpretation of interaction
between LECHDE and dark matter is described. We obtain a relation between the interaction term of dark components and thermal
fluctuation in a non-flat universe, bounded by the apparent horizon. In limiting case, for ordinary HDE, the relation of interaction
term versus thermal fluctuation is also calculated. 相似文献
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M. Salti 《International Journal of Theoretical Physics》2013,52(12):4583-4591
The main goal of the present work is to investigate the validity of the second law of gravitational thermodynamics in an expanding Gödel-type universe filled with generalized Chaplygin gas interacting with cold dark matter. By assuming the Universe as a thermodynamical system bounded by the apparent horizon, and calculating separately the entropy variation for generalized Chaplygin gas, cold dark matter and for the horizon itself, we obtained an expression for the time derivative of the total entropy. We conclude that the 2nd law of gravitational thermodynamics is conditionally valid in the cosmological scenario where the generalized Chaplygin gas interacts with cold dark matter. 相似文献
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In this paper, we study the evolution of a spatially flat universe composed of Tsallis agegraphic dark energy(TADE) and a pressureless dark matter(DM), by assuming that there is a signchangeable interaction between TADE and DM. The density, deceleration parameter and the equation of state parameters(EoS) show satisfactory behaviors in the model. By analysis we find that the accelerated expansion of the universe can be achieved at the late time if model parameters δ2 and -2/3β0. Also, we investigate the interacting TADE model by means of statefinder diagnostic and w–w' analysis. 相似文献
20.
We study thermodynamics of the parabolic Lemaitre-Tolman-Bondi (LTB) cosmology supported by a perfect fluid source. This model is the natural generalization of the flat Friedmann-Robertson-Walker (FRW) universe, and describes an inhomogeneous universe with spherical symmetry. After reviewing some basic equations in the parabolic LTB cosmology, we obtain a relation for the deceleration parameter in this model. We also obtain a condition for which the universe undergoes an accelerating phase at the present time. We use the first law of thermodynamics on the apparent horizon together with the Einstein field equations to get a relation for the apparent horizon entropy in LTB cosmology. We find out that in LTB model of cosmology, the apparent horizon's entropy could be feeded by a term, which incorporates the effects of the inhomogeneity. We consider this result and get a relation for the total entropy evolution, which is used to examine the generalized second law of thermodynamics for an accelerating universe. We also verify the validity of the second law and the generalized second law of thermodynamics for a universe filled with some kinds of matters bounded by the event horizon in the framework of the parabolic LTB model. 相似文献