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arXiv · 2410.04500

Regular models of ramified unitary Shimura varieties at maximal parahoric level

Qiao He·Yu Luo·Yousheng Shi
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Abstract

We use the idea of splitting models to define and study a semi-stable model for unitary Shimura varieties of signature $(n-1,1)$ with maximal parahoric level structure at ramified primes. In this case, the ``naive'' splitting model defined by Pappas and Rapoport fails to be flat in a crucial way. We prove that the genuine splitting model in this case is flat with semi-stable reduction.

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Qiao He, Yu Luo, Yousheng Shi. 2024-10-06. Regular models of ramified unitary Shimura varieties at maximal parahoric level. https://arxiv.org/abs/2410.04500

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