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arXiv · 2505.09015

Fedder-type criterion for quasi-$F^e$-splitting and quasi-$F$-regularity

Shou Yoshikawa
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Abstract

We study quasi-$F^e$-split and quasi-$F$-regular singularities, which generalize Yobuko's quasi-$F$-splitting. We establish Fedder type criteria that characterize these properties for hypersurfaces. These criteria offer explicit tools for computation and verification. As an application, we construct a counterexample to the inversion of adjunction for quasi-$F$-regularity and compute the quasi-$F$-split threshold of the cone over the ordinary cusp.

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Shou Yoshikawa. 2025-05-13. Fedder-type criterion for quasi-$F^e$-splitting and quasi-$F$-regularity. https://arxiv.org/abs/2505.09015

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