4,666 research outputs found

    Labor Solidarity In the New World Order: The UMWA Program in Colombia

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    [Excerpt] Globalization of capital is not a new problem, but it is a persistent and growing one. Capital\u27s ability to search the world over for the cheapest labor enables corporations to maintain oppressive working conditions and leads to downward pressures on living and working standards throughout the world. U.S. coal miners and their union, the United Mine Workers of America (UMWA), realized many years ago that waging struggles in this country was not enough to successfully deal with the reality of job and capital flight to repressive, low-wage countries. Just using the old methods won\u27t work anymore. We must also join forces across industry lines and national boundaries if we want to be successful. And we must come up with new and creative means to confront corporate power. But it often takes years of developing relationships and working together to develop the close bonds and trust that are necessary for effective solidarity. The UMWA has been forging these bonds with the Colombian mine workers\u27 union, Sindicato de los Trabajadores del Intercor (SlNTERCOR), since 1988. Forging alliances is only half the work of effective international solidarity. Unions also need comprehensive strategies that attack corporations from every possible angle. Only by employing an arsenal of different approaches can we ever hope to confront a multinational corporation as huge and powerful as Exxon

    Vortex Glass is a Metal: Unified Theory of the Magnetic Field and Disorder-Tuned Bose Metals

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    We consider the disordered quantum rotor model in the presence of a magnetic field. We analyze the transport properties in the vicinity of the multicritical point between the superconductor, phase glass and paramagnetic phases. We find that the magnetic field leaves metallic transport of bosons in the glassy phase in tact. In the vicinity of the vicinity of the superconductivity-to-Bose metal transition, the resistitivy turns on as (H−Hc)2(H-H_c)^{2} with HcH_c. This functional form is in excellent agreement with the experimentally observed turn-on of the resistivity in the metallic state in MoGe, namely R≈Rc(H−Hc)μR\approx R_c(H-H_c)^\mu, 1<μ<31<\mu<3. The metallic state is also shown to presist in three spatial dimensions. In addition, we also show that the metallic state remains intact in the presence of Ohmic dissipation in spite of recent claims to the contrary. As the phase glass in d=3d=3 is identical to the vortex glass, we conclude that the vortex glass is, in actuality, a metal rather than a superconductor at T=0. Our analysis unifies the recent experiments on vortex glass systems in which the linear resistivity remained non-zero below the putative vortex glass transition and the experiments on thin films in which a metallic phase has been observed to disrupt the direct transition from a superconductor to an insulator.Comment: Published version with an appendix showing that the claim in cond-mat/0510380 (and cond-mat/0606522) that Ohmic dissipation in the phase glass leads to a superconducting state is false. A metal persists in this case as wel

    On the sign of kurtosis near the QCD critical point

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    We point out that the quartic cumulant (and kurtosis) of the order parameter fluctuations is universally negative when the critical point is approached on the crossover side of the phase separation line. As a consequence, the kurtosis of a fluctuating observable, such as, e.g., proton multiplicity, may become smaller than the value given by independent Poisson statistics. We discuss implications for the Beam Energy Scan program at RHIC.Comment: 4 pages, 2 figure

    The Renormalization Group and the Superconducting Susceptibility of a Fermi Liquid

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    A free Fermi gas has, famously, a superconducting susceptibility that diverges logarithmically at zero temperature. In this paper we ask whether this is still true for a Fermi liquid and find that the answer is that it does {\it not}. From the perspective of the renormalization group for interacting fermions, the question arises because a repulsive interaction in the Cooper channel is a marginally irrelevant operator at the Fermi liquid fixed point and thus is also expected to infect various physical quantities with logarithms. Somewhat surprisingly, at least from the renormalization group viewpoint, the result for the superconducting susceptibility is that two logarithms are not better than one. In the course of this investigation we derive a Callan-Symanzik equation for the repulsive Fermi liquid using the momentum-shell renormalization group, and use it to compute the long-wavelength behavior of the superconducting correlation function in the emergent low-energy theory. We expect this technique to be of broader interest.Comment: 9 pages, 2 figure

    Effective Field Theory for the Quantum Electrodynamics of a Graphene Wire

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    We study the low-energy quantum electrodynamics of electrons and holes, in a thin graphene wire. We develop an effective field theory (EFT) based on an expansion in p/p_T, where p_T is the typical momentum of electrons and holes in the transverse direction, while p are the momenta in the longitudinal direction. We show that, to the lowest-order in (p/p_T), our EFT theory is formally equivalent to the exactly solvable Schwinger model. By exploiting such an analogy, we find that the ground state of the quantum wire contains a condensate of electron-hole pairs. The excitation spectrum is saturated by electron-hole collective bound-states, and we calculate the dispersion law of such modes. We also compute the DC conductivity per unit length at zero chemical potential and find g_s =e^2/h, where g_s=4 is the degeneracy factor.Comment: 7 pages, 2 figures. Definitive version, accepted for publication on Phys. Rev.

    Acoustic properties of turbofan inlets

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    The acoustic field within a duct containing a nonuniform steady flow was predicted. This analysis used the finite element method to calculate the velocity potential within the duct

    Interfacial Tensions near Critical Endpoints: Experimental Checks of EdGF Theory

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    Predictions of the extended de Gennes-Fisher local-functional theory for the universal scaling functions of interfacial tensions near critical endpoints are compared with experimental data. Various observations of the binary mixture isobutyric acid ++ water are correlated to facilitate an analysis of the experiments of Nagarajan, Webb and Widom who observed the vapor-liquid interfacial tension as a function of {\it both} temperature and density. Antonow's rule is confirmed and, with the aid of previously studied {\it universal amplitude ratios}, the crucial analytic ``background'' contribution to the surface tension near the endpoint is estimated. The residual singular behavior thus uncovered is consistent with the theoretical scaling predictions and confirms the expected lack of symmetry in (T−Tc)(T-T_c). A searching test of theory, however, demands more precise and extensive experiments; furthermore, the analysis highlights, a previously noted but surprising, three-fold discrepancy in the magnitude of the surface tension of isobutyric acid ++ water relative to other systems.Comment: 6 figure

    Determination of the effects of nozzle nonlinearities upon nonlinear stability of liquid propellant rocket motors

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    The research is reported concerning the development of a three-dimensional nonlinear nozzle admittance relation to be used as a boundary condition in the nonlinear combustion instability theories for liquid propellant rocket engines. The derivation of the nozzle wave equation and the application of the Galerkin method are discussed along with the nozzle response

    Spin dynamics across the superfluid-insulator transition of spinful bosons

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    Bosons with non-zero spin exhibit a rich variety of superfluid and insulating phases. Most phases support coherent spin oscillations, which have been the focus of numerous recent experiments. These spin oscillations are Rabi oscillations between discrete levels deep in the insulator, while deep in the superfluid they can be oscillations in the orientation of a spinful condensate. We describe the evolution of spin oscillations across the superfluid-insulator quantum phase transition. For transitions with an order parameter carrying spin, the damping of such oscillations is determined by the scaling dimension of the composite spin operator. For transitions with a spinless order parameter and gapped spin excitations, we demonstrate that the damping is determined by an associated quantum impurity problem of a localized spin excitation interacting with the bulk critical modes. We present a renormalization group analysis of the quantum impurity problem, and discuss the relationship of our results to experiments on ultracold atoms in optical lattices.Comment: 43 pages (single-column format), 8 figures; v2: corrected discussion of fixed points in Section V
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