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Related papers: Chern-Mather classes of toric varieties

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Macpherson defined Chern-Schwartz-Macpherson (CSM) classes by introducing the (local) Euler obstruction function, which is an integer valued function on the variety that is constant on each stratum of a Whitney stratification of an…

Algebraic Geometry · Mathematics 2018-06-01 Jose Israel Rodriguez

We present an algorithm for the symbolic and numerical computation of the degrees of the Chern-Schwartz-MacPherson classes of a closed subvariety of projective space P^n. As the degree of the top Chern-Schwartz-MacPherson class is the…

Algebraic Geometry · Mathematics 2013-07-02 Christine Jost

We survey recent developments in the study of torus equivariant motivic Chern and Hirzebruch characteristic classes of projective toric varieties, with applications to calculating equivariant Hirzebruch genera of torus-invariant Cartier…

Algebraic Geometry · Mathematics 2024-04-01 Sylvain E. Cappell , Laurenţiu Maxim , Jörg Schürmann , Julius L. Shaneson

We discuss a method for calculating the Chern-Schwartz-MacPherson (CSM) class of a Schubert variety in the Grassmannian using small resolutions introduced by Zelevinsky. As a consequence, we show how to compute the Chern-Mather class and…

Algebraic Geometry · Mathematics 2010-03-15 Benjamin F. Jones

There are several ways to generalize characteristic classes for singular algebraic varieties. The simplest ones to describe are Chern-Mather classes obtained by Nash blow up. They serve as an ingredient to construct…

alg-geom · Mathematics 2007-05-23 Jean-Paul Brasselet , Andrzej Weber

Let $V$ be a possibly singular scheme-theoretic complete intersection subscheme of $\mathbb{P}^n$ over an algebraically closed field of characteristic zero. Using a recent result of Fullwood ("On Milnor classes via invariants of singular…

Algebraic Geometry · Mathematics 2017-11-15 Martin Helmer

We consider equivariant versions of the motivic Chern and Hirzebruch characteristic classes of a quasi-projective toric variety, and extend many known results from non-equivariant to the equivariant setting. The corresponding generalized…

Algebraic Geometry · Mathematics 2025-09-16 Sylvain E. Cappell , Laurenţiu Maxim , Jörg Schürmann , Julius L. Shaneson

We study rank 2 torus-equivariant torsion-free sheaves on the complex projective space. For reflexive sheaves we derive a simple formula for the Chern polynomial, and in the general torsion-free case we introduce an iterative construction…

Algebraic Geometry · Mathematics 2025-11-07 Carl Tipler

We establish a Brauer-Siegel type formula for class numbers of CM tori. We deduce lower bounds for Galois orbits of certain Shimura varieties.

Number Theory · Mathematics 2013-09-11 Emmanuel Ullmo , Andrei Yafaev

Classical and quantum Chern-Simons with gauge group $\text{U}(1)^N$ were classified by Belov and Moore in \cite{belov_moore}. They studied both ordinary topological quantum field theories as well as spin theories. On the other hand a…

High Energy Physics - Theory · Physics 2009-09-29 Spencer D. Stirling

We define the equivariant Chern-Schwartz-MacPherson class of a possibly singular algebraic variety with a group action over the complex number field (or a field of characteristic 0). In fact, we construct a natural transformation from the…

Algebraic Geometry · Mathematics 2009-11-10 Toru Ohmoto

We give a new formula for the Chern-Schwartz-MacPherson class of a hypersurface in a nonsigular compact complex analytic variety. In particular this formula generalizes our previous result on the Euler characteristic of such a hypersurface.…

Algebraic Geometry · Mathematics 2007-05-23 Adam Parusinski , Piotr Pragacz

For a large class of possibly singular complete intersections we prove a formula for their Chern-Schwartz-MacPherson classes in terms of a single blowup along a scheme supported on the singular loci of such varieties. In the hypersurface…

Algebraic Geometry · Mathematics 2016-04-28 James Fullwood , Dongxu Wang

Anna Melnikov provided a parametrization of Borel orbits in the affine variety of square-zero $n \times n$ matrices by the set of involutions in the symmetric group. A related combinatorics leads to a construction a Bott-Samelson type…

Algebraic Geometry · Mathematics 2022-04-13 Piotr Rudnicki , Andrzej Weber

We consider two classical extensions for singular varieties of the usual Chern classes of complex manifolds, namely the total Schwartz-MacPherson and Fulton-Johnson classes, $c^{SM}(X)$ and $c^{FJ}(X)$. Their difference (up to sign) is the…

Algebraic Geometry · Mathematics 2019-11-20 Roberto Callejas-Bedregal , Michelle Morgado , Jose Seade

We calculate Chow quotients of some families of symmetric \(T\)-varieties. In complexity two we obtain new examples of K\"ahler-Einstein metrics by bounding the symmetric alpha invariant of their orbifold quotients. As an additional…

Algebraic Geometry · Mathematics 2019-12-20 Jacob Cable

In this paper, I construct Chern classes in the rigid cohomology of P. Berthelot. We start by constructing Chern classes for proper varieties. To prove all the properties we have to reinterpret the construction in a crystalline way. Then we…

Algebraic Geometry · Mathematics 2007-05-23 Petrequin Denis

We give explicit formulas for the Chern-Schwartz-MacPherson classes of all Schubert varieties in the Grassmannian of $d$-planes in a vector space, and conjecture that these classes are effective. We prove this is the case for (very) small…

Algebraic Geometry · Mathematics 2012-04-11 Paolo Aluffi , Leonardo Constantin Mihalcea

In this work we study characteristic classes of possibly singular varieties embedded as a closed subvariety of a nonsingular variety. In special, we express the Schwartz-MacPherson class in terms of the $\mu$-class and Chern class of the…

Algebraic Geometry · Mathematics 2024-10-04 Antonio M. Ferreira , Fernando Lourenco

For a manifold with boundary, the restriction of Chern's transgression form of the Euler curvature form over the boundary is closed. Its cohomology class is called the secondary Chern-Euler class and used by Sha to formulate a relative…

Differential Geometry · Mathematics 2010-02-08 Zhaohu Nie