166 research outputs found
Phantom Mimicry on the Normal Branch of a DGP-inspired Braneworld Scenario with Curvature Effect
It has been shown recently that phantom-like effect can be realized on the
normal branch of the DGP setup without introduction of any phantom matter
neither in the bulk nor on the brane and therefore without violation of the
null energy condition. It has been shown also that inclusion of the
Gauss-Bonnet term in the bulk action modifies this picture via curvature
effects. Here, based on the Lue-Starkman conjecture on the dynamical screening
of the brane cosmological constant in the DGP setup, we extend this proposal to
a general DGP-inspired model that stringy effects in the
ultra-violet sector of the theory are taken into account by inclusion of the
Gauss-Bonnet term in the bulk action. We study cosmological dynamics of this
setup, especially its phantom-like behavior and possible crossing of the
phantom divide line especially with a non-minimally coupled quintessence field
on the brane. In this setup, scalar field and curvature quintessence are
treated in a unified framework.Comment: 25 Figures, To appear in MPL
Generalized Uncertainty Principle and the Ramsauer-Townsend Effect
The scattering cross section of electrons in noble gas atoms exhibits a
minimum value at electron energies of approximately 1eV. This is the
Ramsauer-Townsend effect. In this letter, we study the Ramsauer-Townsend effect
in the framework of the Generalized Uncertainty Principle.Comment: 11 pages, 3 figure
Noncommutative Inspired Reissner-Nordstr\"om Black Holes in Large Extra Dimensions
Recently, a new noncommutative geometry inspired solution of the coupled
Einstein-Maxwell field equations including black holes in 4-dimension is found.
In this paper, we generalize some aspects of this model to the
Reissner-Nordstr\"om (RN) like geometries with large extra dimensions. We
discuss Hawking radiation process based on noncommutative inspired solutions.
In this framework, existence of black hole remnant and possibility of its
detection in LHC are investigated.Comment: 24 pages, 12 figures, revised version to appear in Commun. Theor.
Phy
Bandgap Narrowing in Quantum Wires
In this paper we consider two different geometry of quasi one-dimensional
semiconductors and calculate their exchange-correlation induced bandgap
renormalization (BGR) as a function of the electron-hole plasma density and
quantum wire width. Based on different fabrication scheme, we define suitable
external confinement potential and then leading-order GW dynamical screening
approximation is used in the calculation by treating electron-electron Coulomb
interaction and electron-optical phonon interaction. Using a numerical scheme,
screened Coulomb potential, probability of different states, profile of charge
density and the values of the renormalized gap energy are calculated and the
effects of variation of confinement potential width and temperature are
studied.Comment: 17 Pages, 4 Figure
On the dissipative non-minimal braneworld inflation
We study the effects of the non-minimal coupling on the dissipative dynamics
of the warm inflation in a braneworld setup, where the inflaton field is
non-minimally coupled to induced gravity on the warped DGP brane. We study with
details the effects of the non-minimal coupling and dissipation on the
inflationary dynamics on the normal DGP branch of this scenario in the
high-dissipation and high-energy regime. We show that incorporation of the
non-minimal coupling in this setup decreases the number of e-folds relative to
the minimal case. We also compare our model parameters with recent
observational data.Comment: 32 pages, 6 figures. arXiv admin note: substantial text overlap with
arXiv:1001.044
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