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arXiv · 2405.19848

Some remarks on Brauer Classes of K3-type

Federica Galluzzi·Bert van Geemen
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Abstract

An element in the Brauer group of a general complex projective $K3$ surface $S$ defines a sublattice of the transcendental lattice of $S$. We consider those elements of prime order for which this sublattice is Hodge-isometric to the transcendental lattice of another K3 surface $X$. We recall that this defines a finite map between moduli spaces of polarized K3 surfaces and we compute its degree. We show how the Picard lattice of $X$ determines the Picard lattice of $S$ in the case that the Picard number of $X$ is two.

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Federica Galluzzi, Bert van Geemen. 2024-05-30. Some remarks on Brauer Classes of K3-type. https://arxiv.org/abs/2405.19848

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