102 research outputs found
Effects of multiple heavy metal contamination and repeated phytoextraction by Sedum plumbizincicola on soil microbial properties
Semiclassical Quantization for the Spherically Symmetric Systems under an Aharonov-Bohm magnetic flux
The semiclassical quantization rule is derived for a system with a
spherically symmetric potential and an
Aharonov-Bohm magnetic flux. Numerical results are presented and compared with
known results for models with . It is shown that the
results provided by our method are in good agreement with previous results. One
expects that the semiclassical quantization rule shown in this paper will
provide a good approximation for all principle quantum number even the rule is
derived in the large principal quantum number limit . We also discuss
the power parameter dependence of the energy spectra pattern in this
paper.Comment: 13 pages, 4 figures, some typos correcte
Statefinder diagnostic and stability of modified gravity consistent with holographic and new agegraphic dark energy
Recently one of us derived the action of modified gravity consistent with the
holographic and new-agegraphic dark energy. In this paper, we investigate the
stability of the Lagrangians of the modified gravity as discussed in [M. R.
Setare, Int. J. Mod. Phys. D 17 (2008) 2219; M. R. Setare, Astrophys. Space
Sci. 326 (2010) 27]. We also calculate the statefinder parameters which
classify our dark energy model.Comment: 12 pages, 2 figures, accepted by Gen. Relativ. Gravi
Holographic dark energy with time varying parameter
We consider the holographic dark energy model in which the model parameter
evolves slowly with time. First we calculate the evolution of EoS
parameter as well as the deceleration parameter in this generalized version of
holographic dark energy (GHDE). Depending on the parameter , the phantom
regime can be achieved earlier or later compare with original version of
holographic dark energy. The evolution of energy density of GHDE model is
investigated in terms of parameter . We also show that the time-dependency
of can effect on the transition epoch from decelerated phase to
accelerated expansion. Finally, we perform the statefinder diagnostic for GHDE
model and show that the evolutionary trajectories of the model in plane
are strongly depend on the parameter .Comment: 16 pages, 4 figures, accepted by Astrophys Space Sc
Cosmological evolution and statefinder diagnostic for new holographic dark energy model in non flat universe
In this paper, the holographic dark energy model with new infrared cut-off
proposed by Granda and Oliveros has been investigated in spatially non flat
universe. The dependency of the evolution of equation of state, deceleration
parameter and cosmological evolution of Hubble parameter on the parameters of
new HDE model are calculated. Also, the statefinder parameters and in
this model are derived and the evolutionary trajectories in plane are
plotted. We show that the evolutionary trajectories are dependent on the model
parameters of new HDE model. Eventually, in the light of SNe+BAO+OHD+CMB
observational data, we plot the evolutionary trajectories in and
planes for best fit values of the parameters of new HDE model.Comment: 11 pages, 5 figures, Accepted by Astrophys. Space Sc
Holographic dark energy in the DGP model
The braneworld model proposed by Dvali, Gabadadze and Porrati leads to an
accelerated universe without cosmological constant or other form of dark
energy. Nevertheless, we have investigated the consequences of this model when
an holo- graphic dark energy is included, taken the Hubble scale as IR cutoff.
We have found that the holographic dark energy leads to an accelerated universe
flat (de Sitter like expansion) for the two branch: {\ko} = \pm1 of the DGP
model. Nevertheless, in universes with no null curvature the dark energy
presents an EoS corresponding to a phantom fluid during the present era and
evolving to a de Sitter like phase for future cosmic time. In the special case
in which the holographic parameter c is equal to one we have found a sudden
singularity in closed universes. In this case the expansion is decelerating.
ManuscriptComment: Latex, 12 pages, 4 figures; Submitted to Phys. Lett.
New Agegraphic Dark Energy in Gravity
In this paper we study cosmological application of new agegraphic dark energy
density in the gravity framework. We employ the new agegraphic model of
dark energy to obtain the equation of state for the new agegraphic energy
density in spatially flat universe. Our calculation show, taking , it is
possible to have crossing -1. This implies that one can
generate phantom-like equation of state from a new agegraphic dark energy model
in flat universe in the modified gravity cosmology framework. Also we develop a
reconstruction scheme for the modified gravity with action.Comment: 8 pages, no figur
Reconstructing interacting new agegraphic polytropic gas model in non-flat FRW universe
We study the correspondence between the interacting new agegraphic dark
energy and the polytropic gas model of dark energy in the non-flat FRW
universe. This correspondence allows to reconstruct the potential and the
dynamics for the scalar field of the polytropic model, which describe
accelerated expansion of the universe.Comment: 9 page
Interacting new agegraphic Phantom model of dark energy in non-flat universe
In this paper we consider the new agegraphic model of interacting dark energy
in non-flat universe. We show that the interacting agegraphic dark energy can
be described by a phantom scalar field. Then we show this phantomic description
of the agegraphic dark energy and reconstruct the potential of the phantom
scalar field.Comment: 8 pages, no figur
The generalized second law for the interacting generalized Chaplygin gas model
We investigate the validity of the generalized second law (GSL) of
gravitational thermodynamics in a non-flat FRW universe containing the
interacting generalized Chaplygin gas with the baryonic matter. The dynamical
apparent horizon is assumed to be the boundary of the universe. We show that
for the interacting generalized Chaplygin gas as a unified candidate for dark
matter (DM) and dark energy (DE), the equation of state parameter can cross the
phantom divide. We also present that for the selected model under thermal
equilibrium with the Hawking radiation, the GSL is always satisfied throughout
the history of the universe for any spatial curvature, independently of the
equation of state of the interacting generalized Chaplygin gas model.Comment: 8 page
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