552,738 research outputs found

    Integer Quantum Hall Effect with Realistic Boundary Condition : Exact Quantization and Breakdown

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    A theory of integer quantum Hall effect(QHE) in realistic systems based on von Neumann lattice is presented. We show that the momentum representation is quite useful and that the quantum Hall regime(QHR), which is defined by the propagator in the momentum representation, is realized. In QHR, the Hall conductance is given by a topological invariant of the momentum space and is quantized exactly. The edge states do not modify the value and topological property of σxy\sigma_{xy} in QHR. We next compute distribution of current based on effective action and find a finite amount of current in the bulk and the edge, generally. Due to the Hall electric field in the bulk, breakdown of the QHE occurs. The critical electric field of the breakdown is proportional to B3/2B^{3/2} and the proportional constant has no dependence on Landau levels in our theory, in agreement with the recent experiments.Comment: 48 pages, figures not included, some additions and revision

    On the pattern of Casimir scaling violation in gluodynamics

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    Results of lattice analysis indicate that the static potential in SU(3) gauge theory is proportional to eigenvalue of quadratic Casimir operator for the corresponding representation with a good accuracy. We discuss the mechanism of possible deviations from the Casimir scaling in gluodynamics in terms of correlators of path-ordered gauge-invariant operators defined on the worldsheet of the confining string.Comment: LaTeX, 12 pages, no figure

    Anomalous dimension and local charges

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    AdS space is the universal covering of a hyperboloid. We consider the action of the deck transformations on a classical string worldsheet in AdS5×S5AdS_5\times S^5. We argue that these transformations are generated by an infinite linear combination of the local conserved charges. We conjecture that a similar relation holds for the corresponding operators on the field theory side. This would be a generalization of the recent field theory results showing that the one loop anomalous dimension is proportional to the Casimir operator in the representation of the Yangian algebra.Comment: 10 pages, LaTeX; v2: added explanations, reference

    A multiplicative potential approach to solutions for cooperative TU-games

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    Concerning the solution theory for cooperative games with transferable utility, it is well-known that the Shapley value is the most appealing representative of the family of (not necessarily efficient) game-theoretic solutions with an additive potential representation. This paper introduces a new solution concept, called Multiplicativily Proportional (MPMP) value, that can be regarded as the counterpart of the Shapley value if the additive potential approach to the solution theory is replaced by a multiplicative potential approach in that the difference of two potential evaluations is replaced by its quotient. One out of two main equivalence theorems states that every solution with a multiplicative potential representation is equivalent to this specifically chosen efficient value in that the solution of the initial game coincides with the MPMP value of an auxiliary game. The associated potential function turns out to be of a multiplicative form (instead of an additive form) with reference to the worth of all the coalitions. The second equivalence theorem presents four additional characterizations of solutions that admit a multiplicative potential representation, e.g., preservation of discrete ratios or path independence

    Coleman-Weinberg Mechanism and Interaction of D3-Branes in Type 0 String Theory

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    The low-energy theory on the world volume of parallel static D3-branes of type 0 strings is the Yang-Mills theory with six scalar fields in the adjoint representation. One-loop corrections in this theory induce Coleman-Weinberg effective potential, which can be interpreted as an interaction energy of D3-branes. The potential is repulsive at short distances and attractive at large ones. In the equilibrium, a large number of D3-branes forms a spherical shell with the radius proportional to the characteristic energy scale of the world-volume theory.Comment: 5 pages, LaTex, 1 figure; v2: Discussion of the interaction potential between D3-branes at short distances is modified, version to be published in Phys. Lett.

    Gluino zero-modes for non-trivial holonomy calorons

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    We couple fermion fields in the adjoint representation (gluinos) to the SU(2) gauge field of unit charge calorons defined on R^3 x S_1. We compute corresponding zero-modes of the Dirac equation. These are relevant in semiclassical studies of N=1 Super-symmetric Yang-Mills theory. Our formulas, show that, up to a term proportional to the vector potential, the modes can be constructed by different linear combinations of two contributions adding up to the total caloron field strength.Comment: 17 pages, 3 Postscript figures, late

    Electoral Rules and Politicians’ Behavior: A Micro Test

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    Theory predicts that the majoritarian electoral system should produce more targeted redistribution and lower politicians’ rents than proportional representation. We test these predictions using micro data for the mixed-member Italian House of Representatives, which allow us to sidestep the identification problems of previous studies based on country-level data. In particular, we address the nonrandom selection into different electoral systems by exploiting a distinctive feature of the Italian two-tier elections from 1994 to 2006: candidates could run for both the majoritarian and the proportional tier, but if they won in both tiers they had to accept the majoritarian seat. Focusing on elections decided by a narrow margin allows us to generate quasi-experimental estimates of the impact of the electoral rule. The main results confirm theoretical predictions, as majoritarian representatives put forward a higher proportion of bills targeted at local areas and show lower absenteeism rates than their proportional colleagues.electoral rule, politicians, targeted redistribution, rent-seeking, regression discontinuity design, treatment effect
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