12,252 research outputs found

    A Note on the Stringy Embeddings of Certain N = 2 Dualities

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    Seiberg-Witten theory can be embedded in F-theory using D3 branes probing an orientifold geometry. The non-perturbative corrections in the orientifold picture map directly to the instanton corrections in the corresponding gauge theory that convert the classical moduli space to the quantum one. In this short review we argue that the recently proposed class of conformal Gaiotto models may also be embedded in F-theory. The F-theory constructions help us not only to understand the Gaiotto dualities but also to extend to the non-conformal cases with and without cascading behaviors. For the conformal cases, the near horizon geometries in F-theory capture both the UV and IR behaviors succinctly.Comment: 6 pages, LaTeX, Based on the talk given by K. D at the Theory Canada Conference June 2012; v2: Typos corrected and references adde

    Effective Superpotentials for SO/Sp with Flavor from Matrix Models

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    We study matrix models related to SO/SpSO/Sp gauge theories with flavors. We give the effective superpotentials for gauge theories with arbitrary tree level superpotential up to first instanton level. For quartic tree level superpotential we obtained exact one-cut solution. We also derive Seiberg-Witten curve for these gauge theories from matrix model argument.Comment: 17pp,2 figures, v2;refs added and to appear in MPL

    A functional central limit theorem for a class of urn models

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    We construct an independent increments Gaussian process associated to a class of multicolor urn models. The construction uses random variables from the urn model which are different from the random variables for which central limit theorems are available in the two color case.Comment: 6 page

    Comparative Statics for a Consumer with Possibly Multiple Optimum Consumption Bundles

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    Non-positivity of the generalized substitution effect, non-positivity of the own-price substitution effect, homogeneity of degree zero in all prices and income, and the law of demand are some of the most primitive comparative static results in the standard revealed preference theory of consumers’ behaviour. These results are however derived for demand functions. The literature does not have corresponding comparative static results for the more plausible case of demand correspondences, where the consumer is permitted to have multiple chosen bundles in a given price-income situation. Using the revealed preference approach to the theory of consumers' behaviour, this note establishes such results for demand correspondences; the analysis can be readily adapted to prove corresponding results in the preference-based approach.demand correspondence, weak axiom of revealed preference, non-positivity of generalized substitution effect, non-positivity of own-price substitution effect, homogeneity of degree zero, law of demand

    Fusion and breakup in the reactions of 6,7Li and 9Be

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    We develop a three body classical trajectory Monte Carlo (CTMC) method to dicsuss the effect of the breakup process on heavy-ion fusion reactions induced by weakly bound nuclei. This method follows the classical trajectories of breakup fragments after the breakup takes place, and thus provides an unambiguous separation between complete and incomplete fusion cross sections. Applying this method to the fusion reaction 6^{6}Li + 209^{209}Bi, we find that there is a significant contribution to the total complete fusion cross sections from the process where all the breakup fragments are captured by the target nucleus (i.e., the breakup followed by complete fusion).Comment: 4 pages, 3 eps figures. Uses espcrc1.sty. To be published in the proceedings of the 8th international conference on clustering aspects of nuclear structure and dynamics, November 24 - 29, 2003, Nara, Japan (Nucl. Phys. A

    Banded spatiotemporal chaos in sheared nematogenic fluids

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    We present the results of a numerical study of a model of the hydrodynamics of a sheared nematogenic fluid, taking into account the effects of order parameter stresses on the velocity profile, but allowing spatial variations only in the gradient direction. When parameter values are such that the stress from orientational distortions is comparable to the bare viscous stress, the system exhibits steady states with the characteristics of shear banding. In addition, nonlinearity in the coupling of extensional flow to orientation leads to the appearance of a new steady state in which the features of both spatiotemporal chaos and shear banding are present.Comment: 4 pages, 6 figures.(Some of the figures have low resolution so as to fit the requirements of arxiv.

    Tunable mechanical and thermal properties of ZnS/CdS core/shell nanowires

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    Using all atom molecular dynamics (MD) simulations, we have studied the mechanical properties of ZnS/CdS core/shell nanowires. Our results show that the coating of a few atomic layer CdS shell on the ZnS nanowire leads to a significant change in the stiffness of the core/shell nanowires compared to the stiffness of pure ZnS nanowires. The binding energy between the core and shell region decreases due to the lattice mismatch at the core-shell interface. This reduction in binding energy plays an important role in determining the stiffness of a core/shell nanowire. We have also investigated the effects of the shell on the thermal conductivity and melting behavior of the nanowires
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