250 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
Crossing of the Phantom Divided Barrier with Lorentz Invariance Violating Fields
We study possible crossing of the phantom divided barrier in a Lorentz
invariance violating dark energy model. Lorentz invariance violation which is
achieved by introducing a vector field in the action, incorporates directly in
the dynamics of the scalar field and equation of state. This interesting
feature allows us to study phantom divided barrier crossing in the context of
Lorentz invariance violation. We show that for suitable choice of parameter
space, equation of state can cross phantom divided barrier just by one scalar
field and Lorentz violating vector field controls this crossing.Comment: 14 pages, 4 figures, Revised and References added, Accepted for
Publication in Europhysics Letter
Loop Quantum Gravity Modification of the Compton Effect
Modified dispersion relations(MDRs) as a manifestation of Lorentz invariance
violation, have been appeared in alternative approaches to quantum gravity
problem. Loop quantum gravity is one of these approaches which evidently
requires modification of dispersion relations. These MDRs will affect the usual
formulation of the Compton effect. The purpose of this paper is to incorporate
the effects of loop quantum gravity MDRs on the formulation of Compton
scattering. Using limitations imposed on MDRs parameters from Ultra High Energy
Cosmic Rays(UHECR), we estimate the quantum gravity-induced wavelength shift of
scattered photons in a typical Compton process. Possible experimental detection
of this wavelength shift will provide strong support for underlying quantum
gravity proposal.Comment: 12 pages, 2 eps figures, revised versio
Entropic force approach in a noncommutative charged black hole and the equivalence principle
Recently, Verlinde has suggested a novel model of duality between
thermodynamics and gravity which leads to an emergent phenomenon for the origin
of gravity and general relativity. In this paper, we investigate some features
of this model in the presence of noncommutative charged black hole by
performing the method of coordinate coherent states representing smeared
structures. We derive several quantities, e.g. temperature, energy and entropic
force. Our approach clearly exhibits that the entropic force on a smallest
fundamental cell of holographic surface with radius is halted.
Accordingly, we can conclude that the black hole remnants are absolutely inert
without gravitational interactions. So, the equivalence principle of general
relativity is contravened due to the fact that it is now possible to find a
difference between the gravitational and inertial mass. In other words, the
gravitational mass in the remnant size does not emit any gravitational field,
therefore it is experienced to be zero, contrary to the inertial mass. This
phenomenon illustrates a good example for a feasible experimental confirmation
to the entropic picture of Newton's Second law in very short distances.Comment: 11 pages, 2 figure
Examining Dimensions and Components and Application of Supply Chain Financing (In Chain Stores)
Purpose: Supply Chain Finance (SCF) is a new approach in financing the working capital of economic enterprises, which can ultimately lead to economic growth and financial stability through efficient and smooth allocation of financial resources, improving financial risk management and increasing financial inclusion. Supply chain financing which runs parallel to the flow of goods and information, is common to all financing networks, and therefore it is important to understand its dimensions. The financing chain provides the cash flow needed to ensure the doors are kept open, the lights are on, employees are paid, and products are produced and shipped.
Methodology: To achieve this goal, SCF uses principles that have been effective in supply chain management (SCM) for decades. The core of this financing chain is to create an optimization plan that can simultaneously control all supply chain financial processes.
Findings: According to these cases, in this paper, considering the importance of managing the financial flow along the chain and using the principles and basics of research in the method of fact-finding and case study, an effort was made by examining the characteristics, dimensions and components of financing in the supply chain. As well as practical experiences in this field, a conceptual framework for the effective use of the financial flow management system as well as its principles and foundations should be provided.
Originality/Value: In this paper, we will examine dimensions and components and application of supply chain financing (in chain stores)
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 characterisations of the input to state stability properties for conformable fractional order bilinear systems
This paper proposes for the first time the theoretical requirements that a fractional-order bilinear system with conformable derivative has to fulfil in order to satisfy different input-to-state stability (ISS) properties. Variants of ISS, namely ISS itself, integral ISS, exponential integral ISS, small-gain ISS, and strong integral ISS for the general class of conformable fractional-order bilinear systems are investigated providing a set of necessary and sufficient conditions for their existence and then compared. Finally, the correctness of the obtained theoretical results is verified by numerical example
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