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arXiv · 2311.18562

Cohomology vanishing for Ekedahl--Oort strata on Hilbert--Blumenthal Shimura varieties

Jean-Stefan Koskivirta
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Abstract

We prove vanishing results for the $0$th cohomology of automorphic line bundles on the Ekedahl--Oort strata of the special fiber of Hilbert--Blumenthal Shimura varieties. This work vastly extends to all Ekedahl--Oort strata previous results of Diamond--Kassaei and Goldring--Koskivirta. Furthermore, our results also cover the case of unitary Shimura varieties of rank $\leq 2$ attached to an arbitrary CM extension. We also prove a conjecture of Goldring--Koskivirta on the set of possible weights of automorphic forms.

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Jean-Stefan Koskivirta. 2023-11-30. Cohomology vanishing for Ekedahl--Oort strata on Hilbert--Blumenthal Shimura varieties. https://arxiv.org/abs/2311.18562

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