منابع مشابه
Contractible classes in toric varieties
Let X be a smooth, complete toric variety. Let A1(X) be the group of algebraic 1-cycles on X modulo numerical equivalence and N1(X) = A1(X) ⊗Z Q . Consider in N1(X) the cone NE(X) generated by classes of curves on X. It is a well-known result due to M. Reid [11] that NE(X) is closed, polyhedral and generated by classes of invariant curves on X. The variety X is projective if and only if NE(X) i...
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For a complete toric variety, we obtain an explicit formula for the localized equivariant Todd class in terms of the combinatorial data – the fan. This is based on the equivariant Riemann-Roch theorem and the computation of the equivariant cohomology and equivariant homology of toric varieties. ∗This research was supported in part by NSF grant DMS-9504522 and DMS-9803593
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Let XΣ be a complete smooth toric variety of dimension n defined by a fan Σ where all Cartier divisors in Pic(XΣ) are nef and let V be a subscheme of XΣ. We show a new expression for the Segre class s(V,XΣ) in terms of the projective degrees of a rational map associated to V . In the case where the number of primitive collections of rays in the fan Σ is equal to the number of generating rays in...
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4.1.5. The weighted projective space P(q0, . . . ,qn), gcd(q0, . . . ,qn) = 1, is built from a fan in N = Z/Z(q0, . . . ,qn). Let ui ∈ N be the image of ei ∈ Z . The dual lattice is M = {(a0, . . . ,an) ∈ Z n+1 | a0q0+ · · ·+anqn = 0}. Also assume that gcd(q0, . . . , q̂i, . . . ,qn) = 1 for i = 0, . . . ,n. (a) Prove that the ui are the primitive ray generators of the fan giving P(q0, . . . ,qn...
متن کاملResidues in toric varieties
We study residues on a complete toric variety X , which are defined in terms of the homogeneous coordinate ring of X . We first prove a global transformation law for toric residues. When the fan of the toric variety has a simplicial cone of maximal dimension, we can produce an element with toric residue equal to 1. We also show that in certain situations, the toric residue is an isomorphism on ...
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ژورنال
عنوان ژورنال: Mathematische Zeitschrift
سال: 2003
ISSN: 0025-5874,1432-1823
DOI: 10.1007/s00209-002-0453-3