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arXiv · 2305.17591

On $F$-pure inversion of adjunction

Thomas Polstra·Austyn Simpson·Kevin Tucker
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Abstract

We analyze adjunction and inversion of adjunction for the $F$-purity of divisor pairs in characteristic $p > 0$. In this vein, we give a complete answer for principal divisors under $\mathbb{Q}$-Gorenstein assumptions but without divisibility restrictions on the index. We also give a detailed analysis relating the $F$-purity of the pairs $(R,\Delta + D)$ and that of $(R_D, \text{Diff}_D(\Delta))$ motivated by Kawakita's log canonical inversion of adjunction via reduction to prime characteristic.

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Thomas Polstra, Austyn Simpson, Kevin Tucker. 2023-05-27. On $F$-pure inversion of adjunction. https://arxiv.org/abs/2305.17591

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