38,877 research outputs found

    New results of intersection numbers on moduli spaces of curves

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    We present a series of new results we obtained recently about the intersection numbers of tautological classes on moduli spaces of curves, including a simple formula of the n-point functions for Witten's τ\tau classes, an effective recursion formula to compute higher Weil-Petersson volumes, several new recursion formulae of intersection numbers and our proof of a conjecture of Itzykson and Zuber concerning denominators of intersection numbers. We also present Virasoro and KdV properties of generating functions of general mixed κ\kappa and ψ\psi intersections.Comment: 9 pages, a brief surve

    Instrument accurately measures small temperature changes on test surface

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    Calorimeter apparatus accurately measures very small temperature rises on a test surface subjected to aerodynamic heating. A continuous thin sheet of a sensing material is attached to a base support plate through which a series of holes of known diameter have been drilled for attaching thermocouples to the material

    The transverse structure of the QCD string

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    The characterization of the transverse structure of the QCD string is discussed. We formulate a conjecture as to how the stress-energy tensor of the underlying gauge theory couples to the string degrees of freedom. A consequence of the conjecture is that the energy density and the longitudinal-stress operators measure the distribution of the transverse position of the string, to leading order in the string fluctuations, whereas the transverse-stress operator does not. We interpret recent numerical measurements of the transverse size of the confining string and show that the difference of the energy and longitudinal-stress operators is the appropriate probe to use when comparing with the next-to-leading order string prediction. Secondly we derive the constraints imposed by open-closed string duality on the transverse structure of the string. We show that a total of three independent `gravitational' form factors characterize the transverse profile of the closed string, and obtain the interpretation of recent effective string theory calculations: the square radius of a closed string of length \beta, defined from the slope of its gravitational form factor, is given by (d-1)/(2\pi\sigma)\log(\beta/(4r_0)) in d space dimensions. This is to be compared with the well-known result that the width of the open-string at mid-point grows as (d-1)/(2\pi\sigma) log(r/r_0). We also obtain predictions for transition form factors among closed-string states.Comment: 21 pages, 1 figur

    Heat sensing instrument Patent

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    Heat sensing instrument, using thermocouple junction connected under heavy conducting materia

    The U.S. economy: a brighter outlook after a bumpy ride

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    Economic conditions - United States
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