250 research outputs found

    Phantom Mimicry on the Normal Branch of a DGP-inspired Braneworld Scenario with Curvature Effect

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    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 f(R,Ď•)f(R,\phi) 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

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    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

    Haemoglobin coventry (β 141 deleted) in iran

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    Loop Quantum Gravity Modification of the Compton Effect

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    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

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    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 r0r_0 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)

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    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

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    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

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    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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