12,066 research outputs found

    Ecosystem Services Beyond Valuation, Regulation and Philanthropy: Integrating Consumer Values into the Economy

    Get PDF
    Environmental Markets, Ecosystem Service Markets, Payment For Ecosystem Services, Incentives, Nature's Services, Resource /Energy Economics and Policy, Q20, Q57, C93, H41,

    VOLUNTARY REVELATION OF THE DEMAND FOR PUBLIC GOODS USING A PROVISION POINT MECHANISM

    Get PDF
    public goods, voluntary contributions, provision point, experiments, information, group size, Resource /Energy Economics and Policy, H41, C92,

    HOMFLY and superpolynomials for figure eight knot in all symmetric and antisymmetric representations

    Full text link
    Explicit answer is given for the HOMFLY polynomial of the figure eight knot 414_1 in arbitrary symmetric representation R=[p]. It generalizes the old answers for p=1 and 2 and the recently derived results for p=3,4, which are fully consistent with the Ooguri-Vafa conjecture. The answer can be considered as a quantization of the \sigma_R = \sigma_{[1]}^{|R|} identity for the "special" polynomials (they define the leading asymptotics of HOMFLY at q=1), and arises in a form, convenient for comparison with the representation of the Jones polynomials as sums of dilogarithm ratios. In particular, we construct a difference equation ("non-commutative A-polynomial") in the representation variable p. Simple symmetry transformation provides also a formula for arbitrary antisymmetric (fundamental) representation R=[1^p], which also passes some obvious checks. Also straightforward is a deformation from HOMFLY to superpolynomials. Further generalizations seem possible to arbitrary Young diagrams R, but these expressions are harder to test because of the lack of alternative results, even partial.Comment: 14 page

    Algebras related to posets of hyperplanes

    Get PDF
    We compare two noncommutative algebras which are related to arrangements of hyperplanes. For three special arrangements the induced approximately finite dimensional CC^*-algebra and the graded Orlik-Solomon-algebra are investigated

    Hopf Bifurcations in a Watt Governor With a Spring

    Full text link
    This paper pursues the study carried out by the authors in "Stability and Hopf bifurcation in a hexagonal governor system", focusing on the codimension one Hopf bifurcations in the hexagonal Watt governor differential system. Here are studied the codimension two, three and four Hopf bifurcations and the pertinent Lyapunov stability coefficients and bifurcation diagrams, ilustrating the number, types and positions of bifurcating small amplitude periodic orbits, are determined. As a consequence it is found an open region in the parameter space where two attracting periodic orbits coexist with an attracting equilibrium point.Comment: 30 pages and 7 figure

    A geometric study of marginally trapped surfaces in space forms and Robertson-Walker spacetimes -- an overview

    Full text link
    A marginally trapped surface in a spacetime is a Riemannian surface whose mean curvature vector is lightlike at every point. In this paper we give an up-to-date overview of the differential geometric study of these surfaces in Minkowski, de Sitter, anti-de Sitter and Robertson-Walker spacetimes. We give the general local descriptions proven by Anciaux and his coworkers as well as the known classifications of marginally trapped surfaces satisfying one of the following additional geometric conditions: having positive relative nullity, having parallel mean curvature vector field, having finite type Gauss map, being invariant under a one-parameter group of ambient isometries, being isotropic, being pseudo-umbilical. Finally, we provide examples of constant Gaussian curvature marginally trapped surfaces and state some open questions.Comment: 21 page
    corecore