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Related papers: Clifford indices for vector bundles on curves

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Clifford indices for semistable vector bundles on a smooth projective curve of genus at least 4 were defined in previous papers of the authors. In the present paper, we establish lower bounds for the Clifford indices for rank 3 bundles. As…

Algebraic Geometry · Mathematics 2009-12-15 H. Lange , P. E. Newstead

Clifford indices for semistable vector bundles on a smooth projective curve of genus at least 4 were defined in a previous paper of the authors. The present paper studies bundles which compute these Clifford indices. We show that under…

Algebraic Geometry · Mathematics 2010-02-15 H. Lange , P. E. Newstead

Let $C$ be a smooth irreducible projective algebraic curve defined over the complex numbers. The notion of the Clifford index of $C$ was extended a few years ago to semistable bundles of any rank. Recent work has been focussed mainly on the…

Algebraic Geometry · Mathematics 2015-01-14 H. Lange , P. E. Newstead

Clifford indices of vector bundles on algebraic curves were introduced in a previous paper of the authors. In this paper we study bundles of rank 2 which compute these Clifford indices. This is of particular interest in the light of…

Algebraic Geometry · Mathematics 2014-01-31 H. Lange , P. E. Newstead

The dimension of spaces of global sections for line bundles on semistable curves parametrized by the compactified Picard scheme is studied. The theorem of Riemann is shown to hold. The theorem of Clifford is shown to hold in the following…

Algebraic Geometry · Mathematics 2010-10-18 Lucia Caporaso

Let $(X,H)$ be a polarized K3 surface with $\mathrm{Pic}(X) = \mathbb Z H$, and let $C\in |H|$ be a smooth curve of genus $g$. We give an upper bound on the dimension of global sections of a semistable vector bundle on $C$. This allows us…

Algebraic Geometry · Mathematics 2018-10-26 Soheyla Feyzbakhsh , Chunyi Li

Let $X$ be a semistable curve and $L$ a line bundle whose multidegree is uniform, i.e., in the range between those of the structure sheaf and the dualizing sheaf of $X$. We establish an upper bound for $h^0(X,L)$, which generalizes the…

Algebraic Geometry · Mathematics 2022-11-02 Karl Christ

This is the author's 2008 thesis from the University of Chicago. We generalize the notion of the Clifford index to an arbitrary very ample line bundle and show how it determines when a curve and its various secant varieties have…

Algebraic Geometry · Mathematics 2010-02-11 Adam Ginensky

In this paper, we determine bundles which compute the higher Clifford indices for trigonal curves.

Algebraic Geometry · Mathematics 2013-05-30 H. Lange , P. E. Newstead

We study the Clifford dimension of an integral curve. To do so, we extend the notion of Clifford index, allowing torsion-free sheaves on its computation. We derive results for arbitrary curves, and then focus on the monomial case. In this…

Algebraic Geometry · Mathematics 2025-07-21 Lia Feital , Naamã Galdino , Renato Vidal Martins , Átila Felipe de Souza

It has been a long-standing problem to find an adequate definition of a Clifford index for higher rank vector bundles on curves, which should capture the complexity of the curve in its moduli space. An interesting proposal in rank 2 has…

Algebraic Geometry · Mathematics 2016-11-23 Benjamin Bakker , Gavril Farkas

We study concepts of stabilities associated to a smooth complex curve together with a linear series on it. In particular we investigate the relation between stability of the associated Dual Span Bundle and linear stability. Our result…

Algebraic Geometry · Mathematics 2023-12-29 Ernesto C. Mistretta , Lidia Stoppino

We extend the notion of Clifford index to reduced curves with planar singularities by considering rank 1 torsion free sheaves. We investigate the behaviour of the Clifford index with respect to the combinatorial properties of the curve and…

Algebraic Geometry · Mathematics 2018-09-24 Marco Franciosi

Two definitions of the Clifford index for vector bundles on a smooth projective curve $C$ of genus $g\ge4$ were introduced in a previous paper by the authors. In another paper the authors obtained results on one of these indices for bundles…

Algebraic Geometry · Mathematics 2014-01-31 H. Lange , P. E. Newstead

In this paper, we remove a technical hypothesis from a previous paper. This allows us to construct stable bundles of rank 2 with Clifford index significantly smaller than the classical Clifford index on suitably chosen curves of any genus…

Algebraic Geometry · Mathematics 2014-01-31 H. Lange , P. E. Newstead

We determine the gonality and the Clifford index for curves on a compact smooth toric surface. Moreover, it is shown that their gonality are computed by pencils on the ambient surface. From the geometrical view point, this means that the…

Algebraic Geometry · Mathematics 2013-10-22 Ryo Kawaguchi

We establish for smooth projective real curves the equivalent of the classical Clifford inequality known for complex curves. We also study the cases when equality holds.

Algebraic Geometry · Mathematics 2007-05-23 Jean-Philippe Monnier

We functorially identify similarity classes of line-bundle-valued quadratic forms on rank two vector bundles with isomorphism classes of pairs consisting of the degree zero and the degree one parts of the associated generalized Clifford…

Algebraic Geometry · Mathematics 2026-02-20 Soham Mondal , T. E. Venkata Balaji

We develop a general theory of Clifford algebras for finite morphisms of schemes and describe applications to the theory of Ulrich bundles and connections to period-index problems for curves of genus 1.

Algebraic Geometry · Mathematics 2025-06-03 Daniel Krashen , Max Lieblich

In this paper we review the notions of gonality and Clifford index of an abstract curve. For a curve embedded in a projective space, we investigate the connection between the \ci of the curve and the \gc al properties of its \emb. In…

Algebraic Geometry · Mathematics 2007-05-23 Robin Hartshorne
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