167,498 research outputs found

    Expanding the thermodynamical potential and the analysis of the possible phase diagram of deconfinement in FL model

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    The deconfinement phase transition is studied in the FL model at finite temperature and chemical potential. At MFT approximation, the phase transition can only be the first order in the whole μT\mu-T phase plane. By a Landau expansion we further study the phase transition order and the possible phase diagram of deconfinement. We discuss the possibilities of second order phase transitions in FL model. By our analysis the cubic term in the Landau expansion could be cancelled by the high order fluctuations. By an ansatz of the Landau parameters, we obtain the possible phase diagram with both first and second order phase transition including the tricritical point which is similar to that of the chiral phase transition.Comment: 7 pages, 8 figures, submitted to Chinese Physics

    Modules-at-infinity for quantum vertex algebras

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    This is a sequel to \cite{li-qva1} and \cite{li-qva2} in a series to study vertex algebra-like structures arising from various algebras such as quantum affine algebras and Yangians. In this paper, we study two versions of the double Yangian DY(sl2)DY_{\hbar}(sl_{2}), denoted by DYq(sl2)DY_{q}(sl_{2}) and DYq(sl2)DY_{q}^{\infty}(sl_{2}) with qq a nonzero complex number. For each nonzero complex number qq, we construct a quantum vertex algebra VqV_{q} and prove that every DYq(sl2)DY_{q}(sl_{2})-module is naturally a VqV_{q}-module. We also show that DYq(sl2)DY_{q}^{\infty}(sl_{2})-modules are what we call VqV_{q}-modules-at-infinity. To achieve this goal, we study what we call §\S-local subsets and quasi-local subsets of \Hom (W,W((x^{-1}))) for any vector space WW, and we prove that any §\S-local subset generates a (weak) quantum vertex algebra and that any quasi-local subset generates a vertex algebra with WW as a (left) quasi module-at-infinity. Using this result we associate the Lie algebra of pseudo-differential operators on the circle with vertex algebras in terms of quasi modules-at-infinity.Comment: Latex, 48 page

    Magnification of spin Hall effect in bilayer electron gas

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    Spin transport properties of a coupled bilayer electron gas with Rashba spin-orbit coupling are studied. The definition of the spin currents in each layer as well as the corresponding continuity-like equations in the bilayer system are given. The curves of the spin Hall conductivities obtained in each layer exhibit sharp cusps around a particular value of the tunnelling strength and the conductivities undergo sign changes across this point. Our investigation on the impurity effect manifests that an arbitrarily small concentration of nonmagnetic impurities does not suppress the spin Hall conductivity to zero in the bilayer system. Based on these features, an experimental scheme is suggested to detect a magnification of the spin Hall effect.Comment: Revtex 10 pages, 4 figures; largely extended versio

    Parallel approach to sliding window sums

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    Sliding window sums are widely used in bioinformatics applications, including sequence assembly, k-mer generation, hashing and compression. New vector algorithms which utilize the advanced vector extension (AVX) instructions available on modern processors, or the parallel compute units on GPUs and FPGAs, would provide a significant performance boost for the bioinformatics applications. We develop a generic vectorized sliding sum algorithm with speedup for window size w and number of processors P is O(P/w) for a generic sliding sum. For a sum with commutative operator the speedup is improved to O(P/log(w)). When applied to the genomic application of minimizer based k-mer table generation using AVX instructions, we obtain a speedup of over 5X.Comment: 10 pages, 5 figure

    The WiggleZ Dark Energy Survey: Galaxy Evolution at 0.25 ≤ z ≤ 0.75 Using the Second Red-Sequence Cluster Survey

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    We study the evolution of galaxy populations around the spectroscopic WiggleZ sample of star-forming galaxies at 0.25 ≤ z ≤ 0.75 using the photometric catalog from the Second Red-Sequence Cluster Survey (RCS2). We probe the optical photometric properties of the net excess neighbor galaxies. The key concept is that the marker galaxies and their neighbors are located at the same redshift, providing a sample of galaxies representing a complete census of galaxies in the neighborhood of star-forming galaxies. The results are compared with those using the RCS WiggleZ Spare-Fibre (RCS-WSF) sample as markers, representing galaxies in cluster environments at 0.25 ≤ z ≤ 0.45. By analyzing the stacked color-color properties of the WiggleZ neighbor galaxies, we find that their optical colors are not a strong function of indicators of star-forming activities such as EW([O II]) or Galaxy Evolution Explorer (GALEX) near-UV luminosity of the markers. The galaxies around the WiggleZ markers exhibit a bimodal distribution on the color-magnitude diagram, with most of them located in the blue cloud. The optical galaxy luminosity functions (GLFs) of the blue neighbor galaxies have a faint-end slope α of ~ –1.3, similar to that for galaxies in cluster environments drawn from the RCS-WSF sample. The faint-end slope of the GLF for the red neighbors, however, is ~ –0.4, significantly shallower than the ~ –0.7 found for those in cluster environments. This suggests that the buildup of the faint end of the red sequence in cluster environments is in a significantly more advanced stage than that in the star-forming and lower galaxy density WiggleZ neighborhoods. We find that the red galaxy fraction (f_red) around the star-forming WiggleZ galaxies has similar values from z ~ 0.3 to z ~ 0.6 with f_red ~ 0.28, but drops to f_red ~ 0.20 at z gsim 0.7. This change of f_red with redshift suggests that there is either a higher rate of star-forming galaxies entering the luminosity-limited sample at z ≳ 0.7, or a decrease in the quenching rate of star formation at that redshift. Comparing to that in a dense cluster environment, the f_red of the WiggleZ neighbors is both considerably smaller and has a more moderate change with redshift, pointing to the stronger and more prevalent environmental influences on galaxy evolution in high-density regions

    Upper critical field from normal state fluctuations in Bi2_2Sr2_2CuO6+δ_{6+\delta}

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    The in-plane magnetoresistance of an epitaxial Bi2_2Sr2_2CuO6+δ_{6+\delta} thin film was systematically investigated as a function of doping, above TcT_c. The orbital magnetoconductance is used to extract the crossover field line Hc2(T)H_{c2}^*(T) in the fluctuation regime. This field is found in good agreement with the upper critical field obtained from resistivity data below TcT_c, and exhibits a similar upward curvature, thus pointing toward the existence of a critical correlation length. The consequences regarding the nature of the resistive transition are discussed

    Relatedness among cryo-bank bulls of the Yakutian Cattle breed as estimated with microsatellite data

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    We analysed 30 autosomal microsatellites in order to clarify genetic relatedness between these bulls and provide recommendations for the use of their semen in conservation and breed management

    Current dependent fluctuations in a Bi2_2Sr2_2CuO6+δ_{6+\delta} thin film

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    The current dependence of the excess conductivity is measured up to 3Tc\simeq 3 T_c for a Bi2_2Sr2_2CuO6+δ_{6+\delta} thin film, as a function of doping. It is found to be anomalously sensitive to the transport current and to behave as a universal function of T/TcT/T_c in the whole doping range. We discuss these results in the perspective of a granular superconductor with a gapless-like behavior
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