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arXiv · 2308.08879

The Picard index of a surface with torus action

Justus Springer
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Abstract

We consider normal rational projective surfaces with torus action and provide a formula for their Picard index, that means the index of the Picard group inside the divisor class group. As an application, we classify the log del Pezzo surfaces with torus action of Picard number one up to Picard index 10,000.

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Justus Springer. 2023-08-17. The Picard index of a surface with torus action. https://doi.org/10.1007/s13348-024-00443-x

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