41,600 research outputs found

    Predicting the relativistic periastron advance of a binary without curving spacetime

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    Relativistic Newtonian Dynamics, the simple model used previously for predicting accurately the anomalous precession of Mercury, is now applied to predict the periastron advance of a binary. The classical treatment of a binary as a two-body problem is modified to account for the influence of the gravitational potential on spacetime. Without curving spacetime, the model predicts the identical equation for the relativistic periastron advance as the post-Newtonian approximation of general relativity formalism thereby providing further substantiation of this model.Comment: 6 pages, 2 figure

    The scalar complex potential and the Aharonov-Bohm effect

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    The Aharonov-Bohm effect is traditionally attributed to the effect of the electromagnetic 4-potential AA, even in regions where both the electric field E\mathbf{E} and the magnetic field B\mathbf{B} are zero. The AB effect reveals that multiple-valued functions play a crucial role in the description of an electromagnetic field. We argue that the quantity measured by AB experiments is a difference in values of a multiple-valued complex function, which we call a complex potential or {pre-potential. We show that any electromagnetic field can be described by this pre-potential, and give an explicit expression for the electromagnetic field tensor through this potential. The pre-potential is a modification of the two scalar potential functions.Comment: 10 pages 2 figure

    Experience in feeding coal into a liquefaction process development unit

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    A system for preparing coal slurry and feeding it into a high pressure liquefaction plant is described. The system was developed to provide supporting research and development for the Bureau of Mines coal liquefaction pilot plant. Operating experiences are included

    The structural contradictions and constraints on corporate social responsibility: Challenges for corporate social irresponsibility

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    Purpose - This chapter engages critically with the ideas of corporate social responsibility (CSR) and irresponsibility (CSI) in order to examine their utility for the purposes of realizing more socially just and environmentally sustainable social and economic practices. Methodology/approach - The chapter develops Marx's understanding of the twin pressures of class struggle and inter-capitalist competition in setting the limits of agency for corporate actors. It is thus theoretical and discursive in nature. Findings - The findings of the chapter suggest that the scope for corporate agency in relation to responsibility/irresponsibility is severely limited by inter-capitalist competition and capitalist social relations. It therefore argues that those interested in social justice and environmental sustainability should focus on these structural pressures rather than theorizing corporate agency. Social implications - The research suggests that the focus of academic and government attention should be on resolving the contradictions and exploitative social relations inherent in capitalism. Without this emphasis activism, corporate agency and government action will not eradicate the types of problem that advocates of CSR/CSI are concerned about. Originality/value of paper - The value of the paper is that it contests and engages critically with the utility of the notion of CSR and the emergent concept of CSI. It asks proponents of these concepts to think seriously about the structural pressures and constraints within which business and policy makers act. Copyrightr © 2012 by Emerald Group Publishing Limited

    Financial Crises: Recent Experience in U.S. and International Markets

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    macroeconomics, financial crisis, crises, U.S. markets, international markets

    Future directions in kaonic atom physics

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    Recent progress and open problems in kaonic atom physics are presented. A connection between phenomenological deep potentials and the underlying K−NK^-N interaction is established as well as the need for a theory for multinucleon absorption of kaons. K−K^- absorption at rest to specific Λ\Lambda hypernuclei states is briefly discussed.Comment: 6 pages, 3 figures, proceedings of the EXA2011 conference, to appear in Hyperfine Interaction

    The time travel paradox

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    We define the time travel paradox in physical terms and prove its existence by constructing an explicit example. We argue further that in theories -- such as general relativity -- where the spacetime geometry is subject to nothing but differential equations and initial data no paradoxes arise.Comment: Minor changes + an explanatory note concerning the lions with the same world line

    Quasi-Adiabatic Continuation in Gapped Spin and Fermion Systems: Goldstone's Theorem and Flux Periodicity

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    We apply the technique of quasi-adiabatic continuation to study systems with continuous symmetries. We first derive a general form of Goldstone's theorem applicable to gapped nonrelativistic systems with continuous symmetries. We then show that for a fermionic system with a spin gap, it is possible to insert π\pi-flux into a cylinder with only exponentially small change in the energy of the system, a scenario which covers several physically interesting cases such as an s-wave superconductor or a resonating valence bond state.Comment: 19 pages, 2 figures, final version in press at JSTA

    Gaining Comprehensive AIDS Treatment in South Africa

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