22,359,548 research outputs found

    Common Medieval Pigments

    Get PDF
    This paper discusses the pigments used in medieval manuscripts. Specific types of pigments that are examined are earths, minerals, manufactured, and organics. It also focuses on both destructive and non-destructive methods for identifying medieval pigments

    A worldsheet extension of O(d,d;Z)

    Get PDF
    We study superconformal interfaces between N=(1,1) supersymmetric sigma models on tori, which preserve a u(1)^{2d} current algebra. Their fusion is non-singular and, using parallel transport on CFT deformation space, it can be reduced to fusion of defect lines in a single torus model. We show that the latter is described by a semi-group extension of O(d,d;Q), and that (on the level of Ramond charges) fusion of interfaces agrees with composition of associated geometric integral transformations. This generalizes the well-known fact that T-duality can be geometrically represented by Fourier-Mukai transformations. Interestingly, we find that the topological interfaces between torus models form the same semi-group upon fusion. We argue that this semi-group of orbifold equivalences can be regarded as the \alpha' deformation of the continuous O(d,d) symmetry of classical supergravity.Comment: 71 pages, 1 figure, minor additions and correction

    A Decadence Baedeker: D'Annunzio's The Triumph of Death

    Get PDF
    This article investigates how Gabriele D’Annunzio’s The Triumph of Death brings together Nietzsche’s ideas and Wagner’s music and interweaves them with the motifs of literary Decadence and the author’s own particular sexual politics. The novel is an experimental text striving to be a Gesemtkunstswerk, an integrated work that incorporates music, painting, poetry, regional folklore, and private thoughts about personal and national power. I discuss the novel’s themes of violent sexuality and the anxiety of powerlessness and explore their implications for the fascist political aesthetics in which D’Annunzio played a pioneering role

    A D-moduli problem?

    Get PDF
    We point out a generic problem in string-inspired supergravity models with an anomalous U(1)XU(1)_X. A large number of matter multiplets charged under U(1)XU(1)_X remain massless above the supersymmetry-breaking scale because of degeneracy of vacua solving the D-flatness conditions. A toy model is analyzed as an illustration of the mechanism; we find the surprising result that many scalars remain massless after supersymmetry-breaking in a hidden sector.Comment: 11 pages, full postscript also available from http://phyweb.lbl.gov/theorygroup/papers/44856.p

    A lattice estimate of the g_{D^* D pi} coupling

    Get PDF
    We present the results of the first direct determination of the g_{D^* D pi} coupling using lattice QCD. From our simulations in the quenched approximation, we obtain g_{D^* D pi} = 18.8 +/- 2.3^{+1.1}_{-2.0} and hat(g) = 0.67 +/- 0.08^{+0.04}_{-0.06}. It is in agreement with a recent experimental result from CLEO.Comment: Lattice2002(heavyquark), 3 pages, 3 figure

    Flyer: Max Planck Virtual Library

    Get PDF

    Folding a 2-D powder diffraction image into a 1-D scan: a new procedure

    Full text link
    A new procedure aiming at folding a powder diffraction 2-D into a 1-D scan is presented. The technique consists of three steps: tracking the beam centre by means of a Simulated Annealing (SA) of the diffraction rings along the same axis, detector tilt and rotation determination by a Hankel Lanczos Singular Value Decomposition (HLSVD) and intensity integration by an adaptive binning algorithm. The X-ray powder diffraction (XRPD) intensity profile of the standard NIST Si 640c sample is used to test the performances. Results show the robustness of the method and its capability of efficiently tagging the pixels in a 2-D readout system by matching the ideal geometry of the detector to the real beam-sample-detector frame. The whole technique turns out in a versatile and user-friendly tool for the 2ϑ2\vartheta scanning of 2-D XRPD profiles.Comment: 11 pages, 1 table, 2 figure

    Multiple Dp_p-branes as a Dp+2_{p+2}-brane

    Full text link
    From BFSS matrix theory considerations, it is expected that a single Dp+2_{p+2}-brane action can be obtained from N Dp_p-brane action in large N limit. We examine and confirm this expectation by working out the details of DBI and Chern-Simons terms of Dp+2_{p+2}-brane action from Dp_{p}-brane action. We show that the same relation works for non-BPS, as well as BPS branesComment: 14 page
    • 

    corecore