141 research outputs found

    Soft matrix models and Chern-Simons partition functions

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    We study the properties of matrix models with soft confining potentials. Their precise mathematical characterization is that their weight function is not determined by its moments. We mainly rely on simple considerations based on orthogonal polynomials and the moment problem. In addition, some of these models are equivalent, by a simple mapping, to matrix models that appear in Chern-Simons theory. The models can be solved with q deformed orthogonal polynomials (Stieltjes-Wigert polynomials), and the deformation parameter turns out to be the usual qq parameter in Chern-Simons theory. In this way, we give a matrix model computation of the Chern-Simons partition function on S3S^{3} and show that there are infinitely many matrix models with this partition function.Comment: 13 pages, 3 figure

    Universality of a family of Random Matrix Ensembles with logarithmic soft-confinement potentials

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    Recently we introduced a family of U(N)U(N) invariant Random Matrix Ensembles which is characterized by a parameter λ\lambda describing logarithmic soft-confinement potentials V(H)[lnH](1+λ)(λ>0V(H) \sim [\ln H]^{(1+\lambda)} \:(\lambda>0). We showed that we can study eigenvalue correlations of these "λ\lambda-ensembles" based on the numerical construction of the corresponding orthogonal polynomials with respect to the weight function exp[(lnx)1+λ]\exp[- (\ln x)^{1+\lambda}]. In this work, we expand our previous work and show that: i) the eigenvalue density is given by a power-law of the form ρ(x)[lnx]λ1/x\rho(x) \propto [\ln x]^{\lambda-1}/x and ii) the two-level kernel has an anomalous structure, which is characteristic of the critical ensembles. We further show that the anomalous part, or the so-called "ghost-correlation peak", is controlled by the parameter λ\lambda; decreasing λ\lambda increases the anomaly. We also identify the two-level kernel of the λ\lambda-ensembles in the semiclassical regime, which can be written in a sinh-kernel form with more general argument that reduces to that of the critical ensembles for λ=1\lambda=1. Finally, we discuss the universality of the λ\lambda-ensembles, which includes Wigner-Dyson universality (λ\lambda \to \infty limit), the uncorrelated Poisson-like behavior (λ0\lambda \to 0 limit), and a critical behavior for all the intermediate λ\lambda (0<λ<0<\lambda<\infty) in the semiclassical regime. We also comment on the implications of our results in the context of the localization-delocalization problems as well as the NN dependence of the two-level kernel of the fat-tail random matrices.Comment: 10 pages, 13 figure

    Family of solvable generalized random-matrix ensembles with unitary symmetry

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    We construct a very general family of characteristic functions describing Random Matrix Ensembles (RME) having a global unitary invariance, and containing an arbitrary, one-variable probability measure which we characterize by a `spread function'. Various choices of the spread function lead to a variety of possible generalized RMEs, which show deviations from the well-known Gaussian RME originally proposed by Wigner. We obtain the correlation functions of such generalized ensembles exactly, and show examples of how particular choices of the spread function can describe ensembles with arbitrary eigenvalue densities as well as critical ensembles with multifractality.Comment: 4 pages, to be published in Phys. Rev. E, Rapid Com

    Rotationally invariant family of L\'evy like random matrix ensembles

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    We introduce a family of rotationally invariant random matrix ensembles characterized by a parameter λ\lambda. While λ=1\lambda=1 corresponds to well-known critical ensembles, we show that λ1\lambda \ne 1 describes "L\'evy like" ensembles, characterized by power law eigenvalue densities. For λ>1\lambda > 1 the density is bounded, as in Gaussian ensembles, but λ<1\lambda <1 describes ensembles characterized by densities with long tails. In particular, the model allows us to evaluate, in terms of a novel family of orthogonal polynomials, the eigenvalue correlations for L\'evy like ensembles. These correlations differ qualitatively from those in either the Gaussian or the critical ensembles.Comment: 9 pages, 5 figure

    Electronic transport in strongly anisotropic disordered systems: model for the random matrix theory with non-integer beta

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    We study numerically an electronic transport in strongly anisotropic weakly disorderd two-dimensional systems. We find that the conductance distribution is gaussian but the conductance fluctuations increase when anisotropy becomes stronger. We interpret this result by random matrix theory with non-integer symmetry parameter beta, in accordance with recent theoretical work of K.A.Muttalib and J.R.Klauder [Phys.Rev.Lett. 82 (1999) 4272]. Analysis of the statistics of transport paramateres supports this hypothesis.Comment: 8 pages, 7 *.eps figure

    ANALISIS PENERAPAN BRAND IMAGE PADA PRODUK BULOG DI PERUM BULOG DIVRE SULSELBAR DI MAKASSAR

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    Kheidir Ahmad, 2018. Analysis of the application of brand image to Bulog products at the Regional Division of Divre Sulselbar Bulog. Thesis Management Study Program, Faculty of Economics and Business, University of Muhammadiyah Makassar. Supervised by Advisor I Abdul Muttalib and Advisor II M. Hidayat. This study aims to assess the application of brand image to Bulog products at the Regional Division of Divre Sulselbar Bulog. The type of research used in this research is qualitative descriptive research. The data in this study were obtained using in-depth interview techniques and direct observation techniques. The in-depth interview technique was conducted on 1 key informant and 3 non-key informants. The observation technique was carried out by researchers on the brand image of Bulog products. The results of this study indicate that the products at the Bulog Divre Sulselbar Corporation in the application of brand image apply three things, namely, the Favor Ability of Brand Association in the form of price, design, benefits and experience of brand image. Strength of Brand Association in the form of brand uniqueness, brand strength and positive attitude applied in brand image. Uniqueness of brand associations in the form of logos, advertisements, and customers respond to Bulog's product brand. Perum Bulog Divre Sulselbar has implemented a brand image on every product produced by Bulog

    New Class of Random Matrix Ensembles with Multifractal Eigenvectors

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    Three recently suggested random matrix ensembles (RME) are linked together by an exact mapping and plausible conjections. Since it is known that in one of these ensembles the eigenvector statistics is multifractal, we argue that all three ensembles belong to a new class of critical RME with multifractal eigenfunction statistics and a universal critical spectral statitics. The generic form of the two-level correlation function for weak and extremely strong multifractality is suggested. Applications to the spectral statistics at the Anderson transition and for certain systems on the border of chaos and integrability is discussed.Comment: 4 pages RevTeX, resubmitte

    Conductance distribution in disordered quantum wires: Crossover between the metallic and insulating regimes

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    We calculate the distribution of the conductance P(g) for a quasi-one-dimensional system in the metal to insulator crossover regime, based on a recent analytical method valid for all strengths of disorder. We show the evolution of P(g) as a function of the disorder parameter from a insulator to a metal. Our results agree with numerical studies reported on this problem, and with analytical results for the average and variance of g.Comment: 8 pages, 5 figures. Final version (minor changes

    Level Spacing Distribution of Critical Random Matrix Ensembles

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    We consider unitary invariant random matrix ensembles which obey spectral statistics different from the Wigner-Dyson, including unitary ensembles with slowly (~(log x)^2) growing potentials and the finite-temperature fermi gas model. If the deformation parameters in these matrix ensembles are small, the asymptotically translational-invariant region in the spectral bulk is universally governed by a one-parameter generalization of the sine kernel. We provide an analytic expression for the distribution of the eigenvalue spacings of this universal asymptotic kernel, which is a hybrid of the Wigner-Dyson and the Poisson distributions, by determining the Fredholm determinant of the universal kernel in terms of a Painleve VI transcendental function.Comment: 5 pages, 1 figure, REVTeX; restriction on the parameter stressed, figure replaced, refs added (v2); typos (factors of pi) in (35), (36) corrected (v3); minor changes incl. title, version to appear in Phys.Rev.E (v4
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