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Nonexistence of a crepant resolution of some moduli spaces of sheaves on a K3 surface

Jaeyoo Choy·Young-Hoon Kiem
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Abstract

Let $M_c=M(2,0,c)$ be the moduli space of O(1)-semistable rank 2 torsion-free sheaves with Chern classes $c_1=0$ and $c_2=c$ on a K3 surface $X$ where O(1) is a generic ample line bundle on $X$. When $c=2n\geq4$ is even, $M_c$ is a singular projective variety equipped with a symplectic structure on the smooth locus. In this paper, we show that there is no crepant resolution of $M_{2n}$ for $n\geq 3$. This implies that there is no symplectic desingularization.

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Jaeyoo Choy, Young-Hoon Kiem. 2005-04-10. Nonexistence of a crepant resolution of some moduli spaces of sheaves on a K3 surface. https://arxiv.org/abs/math/0407100

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