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arXiv · 1903.10116

On del Pezzo fibrations in positive characteristic

Fabio Bernasconi·Hiromu Tanaka
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Abstract

We establish two results on three-dimensional del Pezzo fibrations in positive characteristic. First, we give an explicit bound for torsion index of relatively torsion line bundles. Second, we show the existence of purely inseparable sections with explicit bounded degree. To prove these results, we study log del Pezzo surfaces defined over imperfect fields.

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Fabio Bernasconi, Hiromu Tanaka. 2019-03-25. On del Pezzo fibrations in positive characteristic. https://doi.org/10.1017/s1474748020000067

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