530 research outputs found

    Deformation of Schild String

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    We attempt to construct new superstring actions with a DD-plet of Majorana fermions ψAB\psi^{\cal B}_A, where B{\cal B} is the DD dimensional space-time index and AA is the two dimensional spinor index, by deforming the Schild action. As a result, we propose three kinds of actions: the first is invariant under N=1 (the world-sheet) supersymmetry transformation and the area-preserving diffeomorphism. The second contains the Yukawa type interaction. The last possesses some non-locality because of bilinear terms of ψAB\psi^{\cal B}_A. The reasons why completing a Schild type superstring action with ψAB\psi^{\cal B}_A is difficult are finally discussed.Comment: 12 pages, Latex, both title and abstract are changed, discussion of some relations among our results, Nambu-Goto string and super Yang-Mills theories, added. Results unchange

    On balanced complementation for regular t-wise balanced designs

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    AbstractVanstone has shown a procedure, called r-complementation, to construct a regular pairwise balanced design from an existing regular pairwise balanced design. In this paper, we give a generalization of r-complementation, called balanced complementation. Necessary and sufficient conditions for balanced complementation which gives a regular t-wise balanced design from an existing regular t-wise balanced design are shown. We characterize those aspects of designs which permit balanced complementation. Results obtained here will be applied to construct regular t-wise balanced designs which are useful in Statistics

    Moments of a single entry of circular orthogonal ensembles and Weingarten calculus

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    Consider a symmetric unitary random matrix V=(vij)1i,jNV=(v_{ij})_{1 \le i,j \le N} from a circular orthogonal ensemble. In this paper, we study moments of a single entry vijv_{ij}. For a diagonal entry viiv_{ii} we give the explicit values of the moments, and for an off-diagonal entry vijv_{ij} we give leading and subleading terms in the asymptotic expansion with respect to a large matrix size NN. Our technique is to apply the Weingarten calculus for a Haar-distributed unitary matrix.Comment: 17 page

    Computational algebraic methods in efficient estimation

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    A strong link between information geometry and algebraic statistics is made by investigating statistical manifolds which are algebraic varieties. In particular it it shown how first and second order efficient estimators can be constructed, such as bias corrected Maximum Likelihood and more general estimators, and for which the estimating equations are purely algebraic. In addition it is shown how Gr\"obner basis technology, which is at the heart of algebraic statistics, can be used to reduce the degrees of the terms in the estimating equations. This points the way to the feasible use, to find the estimators, of special methods for solving polynomial equations, such as homotopy continuation methods. Simple examples are given showing both equations and computations. *** The proof of Theorem 2 was corrected by the latest version. Some minor errors were also corrected.Comment: 21 pages, 5 figure

    Fabrication and characterization of high-T/sub c/ SQUID magnetometer with damping resistance

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    General moments of the inverse real Wishart distribution and orthogonal Weingarten functions

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    Let WW be a random positive definite symmetric matrix distributed according to a real Wishart distribution and let W1=(Wij)i,jW^{-1}=(W^{ij})_{i,j} be its inverse matrix. We compute general moments E[Wk1k2Wk3k4...Wk2n1k2n]\mathbb{E} [W^{k_1 k_2} W^{k_3 k_4} ... W^{k_{2n-1}k_{2n}}] explicitly. To do so, we employ the orthogonal Weingarten function, which was recently introduced in the study for Haar-distributed orthogonal matrices. As applications, we give formulas for moments of traces of a Wishart matrix and its inverse.Comment: 29 pages. The last version differs from the published version, but it includes Appendi

    Photon generation by laser-Compton scattering at the KEK-ATF

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    We performed a photon generation experiment by laser-Compton scattering at the KEK-ATF, aiming to develop a Compton based polarized positron source for linear colliders. In the experiment, laser pulses with a 357 MHz repetition rate were accumulated and their power was enhanced by up to 250 times in the Fabry-Perot optical resonant cavity. We succeeded in synchronizing the laser pulses and colliding them with the 1.3 GeV electron beam in the ATF ring while maintaining the laser pulse accumulation in the cavity. As a result, we observed 26.0 +/- 0.1 photons per electron-laser pulse crossing, which corresponds to a yield of 10^8 photons in a second.Comment: 3 pages, 5 figures, Preprint submitted to TIPP09 Proceedings in NIM

    EXAMINATION OF THE TERRAIN EFFECT FOR TERRESTRIAL ALBEDO ESTIMATION VIA BRDF MODEL PARAMETERS

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    ISPRS Technical Commission III WG III/2, 10 Joint Workshop “Multidisciplinary Remote Sensing for Environmental Monitoring”, 12–14 March 2019, Kyoto, JapanIn this paper, we examine the effect of terrain on terrestrial albedo estimation. Terrestrial albedo is one of the most important parameters for understanding the global heat balance. The existing approach for estimating terrestrial albedo involves the estimation of model parameters of the bidirectional reflectance distribution function (BRDF) based on measurements obtained at different geometries. Then, narrowband albedos are estimated from the BRDF model parameters and the broadband albedo is finally estimated by narrowband-tobroadband conversion. Previous studies have not considered the terrain effect for generating the terrestrial albedo. Experiments using in situ measurements showed that the BRDF model, which transforms the geocoordinate of the reflectance of the shadowed terrain, generates the best accuracy. The improvement in the accuracy by the terrain effect correction is limited, and therefore further investigations using more in situ and simulated data are necessary for operational products

    Design of a Polarised Positron Source Based on Laser Compton Scattering

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    We describe a scheme for producing polarised positrons at the ILC from polarised X-rays created by Compton scattering of a few-GeV electron beam off a CO2 or YAG laser. This scheme is very energy effective using high finesse laser cavities in conjunction with an electron storage ring.Comment: Proposal submitted to the ILC workshop, Snowmass 2005. v2: note number adde
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