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On the Brill-Noether theory for K3 surfaces

Maxim Leyenson (2012)

Open Mathematics

Let (S, H) be a polarized K3 surface. We define Brill-Noether filtration on moduli spaces of vector bundles on S. Assume that (c 1(E), H) > 0 for a sheaf E in the moduli space. We give a formula for the expected dimension of the Brill-Noether subschemes. Following the classical theory for curves, we give a notion of Brill-Noether generic K3 surfaces. Studying correspondences between moduli spaces of coherent sheaves of different ranks on S, we prove our main theorem: polarized K3 surface which...

On the cohomological strata of families of vector bundles on algebraic surfaces

Edoardo Ballico (1991)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

In this Note we study certain natural subsets of the cohomological stratification of the moduli spaces of rank 2 vector bundles on an algebraic surface. In the last section we consider the following problem: take a bundle E given by an extension, how can one recognize that E is a certain given bundle? The most interesting case considered here is the case E = T P 3 t since it applies to the study of codimension 1 meromorphic foliations with singularities on P 3 .

On the S-fundamental group scheme

Adrian Langer (2011)

Annales de l’institut Fourier

We introduce a new fundamental group scheme for varieties defined over an algebraically closed (or just perfect) field of positive characteristic and we use it to study generalization of C. Simpson’s results to positive characteristic. We also study the properties of this group and we prove Lefschetz type theorems.

On the strange duality conjecture for abelian surfaces

Alina Marian, Dragos Oprea (2014)

Journal of the European Mathematical Society

We study Le Potier's strange duality conjecture for moduli spaces of sheaves over generic abelian surfaces. We prove the isomorphism for abelian surfaces which are products of elliptic curves, when the moduli spaces consist of sheaves of equal ranks and ber degree 1. The birational type of the moduli space of sheaves is also investigated. Generalizations to arbitrary product elliptic surfaces are given.

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