12,310 research outputs found

    Heuristic Classification of Physical Theories based on Quantum Correlations

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    Taking quantum formalism as a point of reference and connection, we explore the various possibilities that arise in the construction of physical theories. Analyzing the distinct physical phenomena that each of them may describe, we introduce the different types of hidden variables theories that correspond to these physical phenomena. A hierarchical classification of the offered theories, based on the degree of correlation between dichotomic observables in bipartite systems, as quantified by a Bell type inequality, is finally proposed.Comment: 13 pages, 2 figure

    Partial symmetry and existence of least energy solutions to some nonlinear elliptic equations on Riemannian models

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    We consider least energy solutions to the nonlinear equation −Δgu=f(r,u)-\Delta_g u=f(r,u) posed on a class of Riemannian models (M,g)(M,g) of dimension n≥2n\ge 2 which include the classical hyperbolic space Hn\mathbb H^n as well as manifolds with unbounded sectional geometry. Partial symmetry and existence of least energy solutions is proved for quite general nonlinearities f(r,u)f(r,u), where rr denotes the geodesic distance from the pole of MM

    A new approach to the design of wide-band multiprobe reflectometers

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    A new design approach for low-cost multiprobe reflectometers is presented. While traditional circuits adopt equally-spaced probes, the presented solution provide a method to greatly enhance the bandwidth of the measuring system by a proper choice of each probe position. As example, a five-probe 0.6-16 GHz system has been designed

    Separation of Powers, Line Item Veto and the Tax Level: Evidence from the American States Draft 1

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    Line item veto, a feature present in most American States, gives the governor the power to veto single appropriation items from the budget. Its effects on the tax level, however, are still controversial in the empirical and theoretical literature (cf. Holtz-Eakins (1988) and Besley and Case (2003)). Line item veto is mostly a time invariant feature and to asses its effects previous studies have interacted it with political control variables such as a divided government. The endogenity problems that arise from using a political variable to explain a policy variable, however, have not been dealt with in these studies. We use three empirical approaches to tackle the problem and show that line item veto does have a significant negative effect on the tax rate in the States: diffs-in-diffs estimation with instrumental variables (election results in lower offices at the state level), regression discontinuity design, and a dynamic panel. Our prior on its effects comes from adapting the separation of powers model by Persson, Roland and Tabellini (2000) to the American States setup: we add line item veto and an executive. Our model delivers a clear prediction on the tax level, on the amount of public good, and on the importance of group specific transfers.
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