169 research outputs found

    On a singular variety associated to a polynomial mapping

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    In the paper "Geometry of polynomial mapping at infinity via intersection homology" the second and third authors associated to a given polynomial mapping F : \C^2 \to \C^2 with nonvanishing jacobian a variety whose homology or intersection homology describes the geometry of singularities at infinity of the mapping. We generalize this result.Comment: 1 figur

    A New Large N Expansion for General Matrix-Tensor Models

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    We define a new large NN limit for general O(N)R\text{O}(N)^{R} or U(N)R\text{U}(N)^{R} invariant tensor models, based on an enhanced large NN scaling of the coupling constants. The resulting large NN expansion is organized in terms of a half-integer associated with Feynman graphs that we call the index. This index has a natural interpretation in terms of the many matrix models embedded in the tensor model. Our new scaling can be shown to be optimal for a wide class of non-melonic interactions, which includes all the maximally single-trace terms. Our construction allows to define a new large DD expansion of the sum over diagrams of fixed genus in matrix models with an additional O(D)r\text{O}(D)^{r} global symmetry. When the interaction is the complete vertex of order R+1R+1, we identify in detail the leading order graphs for RR a prime number. This slightly surprising condition is equivalent to the complete interaction being maximally single-trace.Comment: 57 pages, 20 figures (additional discussion in Sec. 4.1.1. and additional figure (Fig. 5)

    Poincaré duality for LpL^{p} cohomology on subanalytic singular spaces

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    We investigate the problem of Poincaré duality for LpL^{p} differential forms on bounded subanalytic submanifolds of Rn (not necessarily compact). We show that, when p is sufficiently close to 1 then the LpL^{p} cohomology of such a submanifold is isomorphic to its singular homology. In the case where p is large, we show that Lp cohomology is dual to intersection homology. As a consequence, we can deduce that the LpL^{p} cohomology is Poincaré dual to Lq cohomology, if p and q are Hölder conjugate to each other and p is sufficiently large

    LL^\infty cohomology is intersection cohomology

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    Let XX be any subanalytic compact pseudomanifold. We show a De Rham theorem for LL^\infty forms. We prove that the cohomology of LL^\infty forms is isomorphic to intersection cohomology in the maximal perversity.Comment: Appendix on subanalytic geometry adde

    A Lefschetz duality for intersection homology

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    We prove a Lefschetz duality theorem for intersection homology. Usually, this result applies to pseudomanifolds with boundary which are assumed to have a “collared neighborhood of their boundary”. Our duality does not need this assumption and is a generalization of the classical one
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