1,143 research outputs found

    Poisson Algebra of Wilson Loops in Four-Dimensional Yang-Mills Theory

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    We formulate the canonical structure of Yang--Mills theory in terms of Poisson brackets of gauge invariant observables analogous to Wilson loops. This algebra is non--trivial and tractable in a light--cone formulation. For U(N) gauge theories the result is a Lie algebra while for SU(N) gauge theories it is a quadratic algebra. We also study the identities satsfied by the gauge invariant observables. We suggest that the phase space of a Yang--Mills theory is a co--adjoint orbit of our Poisson algebra; some partial results in this direction are obtained.Comment: 32 Pages, 7 figures upon reques

    Geometric Quantization and Two Dimensional QCD

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    In this article, we will discuss geometric quantization of 2d QCD with fermionic and bosonic matter fields. We identify the respective large-N_c phase spaces as the infinite dimensional Grassmannian and the infinite dimensional Disc. The Hamiltonians are quadratic functions, and the resulting equations of motion for these classical systems are nonlinear. In a previous publication, the first author has shown that the linearization of the equations of motion for the Grassmannian gave the `t Hooft equation. We will see that the linearization in the bosonic case leads to the scalar analog of the `t Hooft equation found by Tomaras.Comment: 46 pages, Latex, no figure

    Catalytic Conversion Probabilities for Bipartite Pure States

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    For two given bipartite-entangled pure states, an expression is obtained for the least upper bound of conversion probabilities using catalysis. The attainability of the upper bound can also be decided if that bound is less than one.Comment: 4 pages; comments appreciated; the article is a modified version of this preprint combined with arXiv:0707.044

    Yang-Mills Theory on a Cylinder Coupled to Point Particles

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    We study a model of quantum Yang-Mills theory with a finite number of gauge invariant degrees of freedom. The gauge field has only a finite number of degrees of freedom since we assume that space-time is a two dimensional cylinder. We couple the gauge field to matter, modeled by either one or two nonrelativistic point particles. These problems can be solved {\it without any gauge fixing}, by generalizing the canonical quantization methods of Ref.\[rajeev] to the case including matter. For this, we make use of the geometry of the space of connections, which has the structure of a Principal Fiber Bundle with an infinite dimensional fiber. We are able to reduce both problems to finite dimensional, exactly solvable, quantum mechanics problems. In the case of one particle, we find that the ground state energy will diverge in the limit of infinite radius of space, consistent with confinement. In the case of two particles, this does not happen if they can form a color singlet bound state (`meson').Comment: 37 pages, UR-1327 ER-40685-77

    Poisson Algebra of Wilson Loops and Derivations of Free Algebras

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    We describe a finite analogue of the Poisson algebra of Wilson loops in Yang-Mills theory. It is shown that this algebra arises in an apparently completely different context; as a Lie algebra of vector fields on a non-commutative space. This suggests that non-commutative geometry plays a fundamental role in the manifestly gauge invariant formulation of Yang-Mills theory. We also construct the deformation of the loop algebra induced by quantization, in the large N_c limit.Comment: 20 pages, no special macros necessar

    Multifacility location problems on a sphere

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    A unified approach to multisource location problems on a sphere is presented. Euclidean, squared Euclidean and the great circle distances are considered. An algorithm is formulated and its convergence properties are investigated

    Hadron Production in Neutrino-Nucleon Interactions at High Energies

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    The multi-particle production at high energy neutrino- nucleon collisions are investigated through the analysis of the data of the experiment CERN-WA-025 at neutrino energy less than 260GeV and the experiments FNAL-616 and FNAL-701 at energy range 120-250 GeV. The general features of these experiments are used as base to build a hypothetical model that views the reaction by a Feynman diagram of two vertices. The first of which concerns the weak interaction between the neutrino and the quark constituents of the nucleon. At the second vertex, a strong color field is assumed to play the role of particle production, which depend on the momentum transferred from the first vertex. The wave function of the nucleon quarks are determined using the variation method and relevant boundary conditions are applied to calculate the deep inelastic cross sections of the virtual diagram.Comment: 6 pages PDF forma

    Symbol calculus and zeta--function regularized determinants

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    In this work, we use semigroup integral to evaluate zeta-function regularized determinants. This is especially powerful for non--positive operators such as the Dirac operator. In order to understand fully the quantum effective action one should know not only the potential term but also the leading kinetic term. In this purpose we use the Weyl type of symbol calculus to evaluate the determinant as a derivative expansion. The technique is applied both to a spin--0 bosonic operator and to the Dirac operator coupled to a scalar field.Comment: Added references, some typos corrected, published versio

    Drying kinetic and physical properties of green laird lentil (Lens culinaris) in microwave drying

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    The objective of this study was to study the drying kinetics of green laird lentil (Lens culinaris) in microwave drying method. The drying data were fitted to the various thin-layer models. All the models were compared using three statistical parameters, that is, coefficient of determination R2, reduced mean square of the deviation X2 and root means square error RMSE. Also, the lentil’s physical and mechanical features crude protein, oil and ash parameters were specified under different microwave levels. It was concluded according to these values that the recommended model is the best model, which can define the drying curves at the practices at 300, 400, 550, 700 and 800 W in drying lentil by microwave.Key words: Microwave, lentil, physical properties, crude protein, drying

    Possible activation of the immune system by chronic peripheral nesfatin-1 application at the acute phase of ischemia/reperfusion injury

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    Objective: Organ transplantation is one of the clinical scenarios involving ischemia and reperfusion process. Ischemia/reperfusion is the pivotal mechanism of organ injury during transplantation. Thus, ischemia/reperfusion (I/R) injury is a biphasic phenomenon that can damage the graft by inflammatory responses. The hypothalamic-pituitary-adrenal (HPA) axis is the main hormonal system that is activated under the influence of stress. Normal HPA axis activity leading to the release of glucocorticoids is essential for homeostasis and survival during stress. Cortisol, a key controller of stress response, is released by the HPA axis. The disrupted release of cortisol in response to inflammation has been shown in animal models. Nesfatin-1 is a peptide involved in the regulation of homeostasis and has anti-inflammatory as well as anti-ischemic properties. Therefore, we aimed to identify the effect of chronic peripheral nesfatin-1 application on the plasma level of cortisol in a rat model of intestinal I/R-based stress. Materials and Methods: Two-month-old 28 Wistar Albino male rats that weighed an average of 200–250 g were used and were randomly divided into the following four experimental groups (n=7): laparotomy, I/R, nesfatin-1+laparotomy, nesfatin-1+I/R. Blood samples were collected in tubes with EDTA. Plasma cortisol levels were analyzed by rat enzyme-linked immunosorbent assay (ELISA) kits. Results: Statistically significant decrease was found in the plasma level of cortisol in nesfatin-1+I/R group compared with I/R group (p=0.026) Conclusion: Nesfatin-1 application can inhibit anti-inflammatory responses under the early phase of intestinal I/R and support immune reactions by reducing plasma cortisol level. This effect of nesfatin-1 may also increase the rejection of grafts during transplantation period. © 2015 by Erciyes University School of Medicine
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