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arXiv · 2609.31781

Torsion proliferation

Joseph Baine·Daniel Tubbenhauer
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Abstract

This paper considers the generic behaviour of sheaves supported on Schubert varieties in finite flag varieties. Our main results are that, for any fixed prime $p$, as the rank of the associated algebraic group grows, almost every intersection cohomology sheaf admits $p$-torsion in its stalks or costalks, and almost every indecomposable parity sheaf is not perverse. For certain families of partial flag varieties we also determine explicit asymptotics for this growth.

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Joseph Baine, Daniel Tubbenhauer. 2026-09-24. Torsion proliferation. https://arxiv.org/abs/2609.31781

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