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arXiv · 2012.10649

The second integral cohomology of moduli spaces of sheaves on K3 and Abelian surfaces

Arvid Perego·Antonio Rapagnetta
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Abstract

In this paper we study the second integral cohomology of moduli spaces of semistable sheaves on projective K3 surfaces. If $S$ is a projective K3 surface, $v$ a Mukai vector and $H$ a $v-$generic polarization on $S$, we show that $H^{2}(M_{v},\mathbb{Z})$ is a free $\mathbb{Z}-$module of rank 23 carrying a pure weight-two Hodge structure and a lattice structure, with respect to which $H^{2}(M_{v},\mathbb{Z})$ is Hodge isometric to the Hodge sublattice $v^{\perp}$ of the Mukai lattice of $S$. Similar results are proved for Abelian surfaces.

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Arvid Perego, Antonio Rapagnetta. 2020-12-19. The second integral cohomology of moduli spaces of sheaves on K3 and Abelian surfaces. https://arxiv.org/abs/2012.10649

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