2,996 research outputs found

    Perturbative quantum gauge fields on the noncommutative torus

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    Using standard field theoretical techniques, we survey pure Yang-Mills theory on the noncommutative torus, including Feynman rules and BRS symmetry. Although in general free of any infrared singularity, the theory is ultraviolet divergent. Because of an invariant regularization scheme, this theory turns out to be renormalizable and the detailed computation of the one loop counterterms is given, leading to an asymptoticaly free theory. Besides, it turns out that non planar diagrams are overall convergent when θ\theta is irrational.Comment: Latex 2e, 19 pages 5 eps figures, typos corrected and 1 reference adde

    Parametric Representation of Rank d Tensorial Group Field Theory: Abelian Models with Kinetic Term sps+μ\sum_{s}|p_s| + \mu

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    We consider the parametric representation of the amplitudes of Abelian models in the so-called framework of rank dd Tensorial Group Field Theory. These models are called Abelian because their fields live on U(1)DU(1)^D. We concentrate on the case when these models are endowed with particular kinetic terms involving a linear power in momenta. New dimensional regularization and renormalization schemes are introduced for particular models in this class: a rank 3 tensor model, an infinite tower of matrix models ϕ2n\phi^{2n} over U(1)U(1), and a matrix model over U(1)2U(1)^2. For all divergent amplitudes, we identify a domain of meromorphicity in a strip determined by the real part of the group dimension DD. From this point, the ordinary subtraction program is applied and leads to convergent and analytic renormalized integrals. Furthermore, we identify and study in depth the Symanzik polynomials provided by the parametric amplitudes of generic rank dd Abelian models. We find that these polynomials do not satisfy the ordinary Tutte's rules (contraction/deletion). By scrutinizing the "face"-structure of these polynomials, we find a generalized polynomial which turns out to be stable only under contraction.Comment: 69 pages, 35 figure

    ALD grown zinc oxide with controllable electrical properties

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    The paper presents results for zinc oxide films grown at low temperature regime by Atomic Layer Deposition (ALD). We discuss electrical properties of such films and show that low temperature deposition results in oxygen-rich ZnO layers in which free carrier concentration is very low. For optimized ALD process it can reach the level of 10^15 cm-3, while mobility of electrons is between 20 and 50 cm2/Vs. Electrical parameters of ZnO films deposited by ALD at low temperature regime are appropriate for constructing of the ZnO-based p-n and Schottky junctions. We demonstrate that such junctions are characterized by the rectification ratio high enough to fulfill requirements of 3D memories and are deposited at temperature 100degC which makes them appropriate for deposition on organic substrates.Comment: 29 pages, 9 figures, 64 references, review pape

    The form factors existing in the b->s g^* decay and the possible CP violating effects in the noncommutative standard model

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    We study the form factors appearing in the inclusive decay b -> s g^*, in the framework of the noncommutative standard model. Here g^* denotes the virtual gluon. We get additional structures and the corresponding form factors in the noncommutative geometry. We analyse the dependencies of the form factors to the parameter p\Theta k where p (k) are the four momenta of incoming (outgoing) b quark (virtual gluon g^*, \Theta is a parameter which measures the noncommutativity of the geometry. We see that the form factors are weaklyComment: 8 pages, 7 figure

    Quantum creep and quantum creep transitions in 1D sine-Gordan chains

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    Discrete sine-Gordon (SG) chains are studied with path-integral molecular dynamics. Chains commensurate with the substrate show the transition from collective quantum creep to pinning at bead masses slightly larger than those predicted from the continuous SG model. Within the creep regime, a field-driven transition from creep to complete depinning is identified. The effects of disorder in the external potential on the chain's dynamics depend on the potential's roughness exponent HH, i.e., quantum and classical fluctuations affect the current self-correlation functions differently for H=1/2H = 1/2.Comment: 4 pages, 3 figure

    Unstable solitons on noncommutative tori and D-branes

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    We describe a class of exact solutions of super Yang-Mills theory on even-dimensional noncommutative tori. These solutions generalize the solitons on a noncommutative plane introduced in hep-th/0009142 that are conjectured to describe unstable D2p-D0 systems. We show that the spectrum of quadratic fluctuations around our solutions correctly reproduces the string spectrum of the D2p-D0 system in the Seiberg-Witten decoupling limit. In particular the fluctuations correctly reproduce the 0-0 string winding modes. For p=1 and p=2 we match the differences between the soliton energy and the energy of an appropriate SYM BPS state with the binding energies of D2-D0 and D4-D0 systems. We also give an example of a soliton that we conjecture describes branes of intermediate dimension on a torus such as a D2-D4 system on a four-torus.Comment: 22 pages, Latex; v.2: references adde

    Why Matrix theory works for oddly shaped membranes

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    We give a simple proof of why there is a Matrix theory approximation for a membrane shaped like an arbitrary Riemann surface. As corollaries, we show that noncompact membranes cannot be approximated by matrices and that the Poisson algebra on any compact phase space is U(infinity). The matrix approximation does not appear to work properly in theories such as IIB string theory or bosonic membrane theory where there is no conserved 3-form charge to which the membranes couple.Comment: 8 pages, 4 figures, revtex; references adde

    Revitalization of selected brownfields in urban space of Skierniewice with particular emphasis on environmentally friendly elements.

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    Transformation of urban space is a result of constant changes, which can also lead to a deterioration of the state of such space. City revitalization programs allow for the release of brownfields from crisis situations and adapting them to the needs of local communities, with particular emphasis on environmentally friendly elements. The aim of the article was to present the concept of revitalization activities, proposed for introduction in the brownfield site, in the city of Skierniewice, currently used by Stal-Car. These activities include treatments that can result in the creation of urban public spaces with environmentally friendly elements.Przekształcenie przestrzeni miejskiej to efekt ciągłych przemian, które mogą prowadzić również do pogorszenia jej stanu. Programy rewitalizacji miast pozwalają na wyprowadzenie ze stanu kryzysowego m.in. terenów poprzemysłowych i dostosowanie ich do wymogów lokalnych społeczności, ze szczególnym uwzględnieniem elementów przyjaznych środowisku. W artykule za cel przyjęto stworzenie koncepcji działań rewitalizacyjnych proponowanych do wprowadzenia na terenie poprzemysłowym w Skierniewicach, obecnie użytkowanym przez firmę Stal-Car. Działania te obejmują zabiegi, których następstwem może być powstanie miejskiej przestrzeni publicznej z elementami przyjaznymi środowisku
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