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Related papers: Stable toric sheaves. I : Chern classes

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In this note, we discuss the concept of pseudoeffective vector bundle and also introduce pseudoeffective torsion-free sheaves over compact K\"ahler manifolds. We show that a pseudoeffective reflexive sheaf over a compact K\"ahler manifold…

Algebraic Geometry · Mathematics 2022-04-29 Xiaojun Wu

We give a complete classification of semistable rank two sheaves on three-dimensional projective space with maximal third Chern character. This implies an explicit description of their moduli spaces. As an open subset they contain rank two…

Algebraic Geometry · Mathematics 2018-11-30 Benjamin Schmidt

We classify Chern characters of semistable sheaves up to rank four in three dimensional projective space. As a corollary we show that moduli spaces of semistable sheaves between rank zero and four with maximal third Chern character are…

Algebraic Geometry · Mathematics 2023-11-08 Benjamin Schmidt

In this paper, we classify several subcategories of the category of coherent sheaves on a noetherian divisorial scheme (e.g. a quasi-projective scheme over a commutative noetherian ring). More precisely, we classify the torsionfree (resp.…

Representation Theory · Mathematics 2023-04-21 Shunya Saito

We give an explicit description of toric sheaves on the weighted projective plane $\mathbb{P}(a,b,c)$ viewed as a toric Deligne-Mumford stack. The integers $(a,b,c)$ are not necessarily chosen coprime or mutually coprime allowing for gerbe…

Algebraic Geometry · Mathematics 2019-02-07 Amin Gholampour , Yunfeng Jiang , Martijn Kool

In this note we give a simple, model-independent construction of Chern classes as natural transformations from differential complex K-theory to differential integral cohomology. We verify the expected behaviour of these Chern classes with…

K-Theory and Homology · Mathematics 2009-07-16 Ulrich Bunke

The moduli space $\mathcal M(r,n)$ of framed torsion free sheaves on the projective plane with rank $r$ and second Chern class equal to $n$ has the natural action of the $(r+2)$-dimensional torus. In this paper, we look at the fixed point…

Algebraic Geometry · Mathematics 2015-06-03 A. Buryak , B. L. Feigin

The purpose of this short note is to prove a formula for the Chern-Mather classes of a toric variety in terms of its orbits and the local Euler obstructions at general points of each orbit (Theorem 2). We use the general definition of the…

Algebraic Geometry · Mathematics 2016-04-12 Ragni Piene

We describe new irreducible components of the moduli space of rank $2$ semistable torsion free sheaves on the three-dimensional projective space whose generic point corresponds to non-locally free sheaves whose singular locus is either…

Algebraic Geometry · Mathematics 2022-08-25 Charles Almeida , Marcos Jardim , Alexander S. Tikhomirov

Let p be an odd prime. We show that for a simply-connected semisimple complex linear algebraic group, if its integral homology has p-torsion, the Chern classes do not generate the Chow ring of its classifying space.

Algebraic Topology · Mathematics 2017-09-05 Masaki Kameko , Nobuaki Yagita

Let $\mathcal{M}$ be the moduli space of rank 2 stable torsion free sheaves with Chern classes $c_i$ on a smooth 3-fold $X$. When $X$ is toric with torus $T$, we describe the $T$-fixed locus of the moduli space. Connected components of…

Algebraic Geometry · Mathematics 2018-06-18 Amin Gholampour , Martijn Kool , Benjamin Young

We first construct closed spherical CR manifolds of dimension at least five having non-trivial first Chern class with real coefficients. We next prove a constraint on Chern classes with real coefficients of (not necessarily closed)…

Differential Geometry · Mathematics 2022-10-13 Yuya Takeuchi

We calculate the equivariant motivic Chern class for configuration space of a quasiprojective (maybe singular) variety and the space of vectors with different directions. We prove the formulas for generating series of these classes. We…

Algebraic Geometry · Mathematics 2021-01-05 Jakub Koncki

Let T be a compact complex torus, dim T>2. We show that the category of coherent sheaves on T is independent of the choice of the complex structure, if this complex structure is generic. The proof is independent of math.AG/0205210, where…

Algebraic Geometry · Mathematics 2007-05-23 Misha Verbitsky

We complete the proof of a theorem we announced and partly proved in [Math. Nachr. 271 (2004), 69-90, math.AG/0111299]. The theorem concerns a family of curves on a family of surfaces. It has two parts. The first was proved in that paper.…

Algebraic Geometry · Mathematics 2022-08-03 Steven Kleiman , Ragni Piene

Let $X$ be a nonsingular variety defined over an algebraically closed field of characteristic $0$, and $D$ be a free divisor. We study the motivic Chern class of $D$ in the Grothendieck group of coherent sheaves $G_0(X)$, and another class…

Algebraic Geometry · Mathematics 2016-12-26 Xia Liao

In "Chern classes for coherent sheaves", H.I. Green constructs Chern classes in de Rham cohomology of coherent analytic sheaves. We construct here a formal $(\infty,1)$-categorical framework into which we can place Green's work and…

Algebraic Geometry · Mathematics 2023-06-28 Timothy Hosgood

We consider a complex smooth projective variety equipped with an action of an algebraic torus with a finite number of fixed points. We compare the motivic Chern classes of Bia{\l}ynicki-Birula cells with the $K$-theoretic stable envelopes…

Algebraic Geometry · Mathematics 2021-11-08 Jakub Koncki

Let ${\mathbb F}_0$ be an algebraically closed field, with $char({\mathbb F}_0)=0$. In this article, for prime numbers $p\geq 2$, we construct smooth affine algebras $B$ over ${\mathbb F}_0$, with $\dim B=p+2$. Further, we construct…

K-Theory and Homology · Mathematics 2026-03-10 Satya Mandal

Given a finite locally free resolution of a coherent analytic sheaf $\mathcal F$, equipped with Hermitian metrics and connections, we construct an explicit current, obtained as the limit of certain smooth Chern forms of $\mathcal F$, that…

Complex Variables · Mathematics 2025-08-28 Richard Lärkäng , Elizabeth Wulcan