Rapoport-Viehmann's local Shimura variety conjecture

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Let (G,[b],{μ})(G,[b],\{\mu\}) be a local Shimura datum over Qp\mathbb{Q}_p, with local reflex field EE, flag variety FℓG,μ\mathscr{F}\ell_{G,\mu} over E˘\breve{E}, weakly admissible locus FℓG,μwa\mathscr{F}\ell_{G,\mu}^{wa}, and associated group JbJ_b. Rapoport–Viehmann's conjecture. There is a tower of rigid analytic spaces (MK)K(\mathcal{M}_K)_K over Sp⁡E˘\operatorname{Sp}\breve{E}, indexed by the open compact subgroups KK of G(Qp)G(\mathbb{Q}_p), such that Jb(Qp)J_b(\mathbb{Q}_p) acts on each MK\mathcal{M}_K, G(Qp)G(\mathbb{Q}_p) acts on the tower by Hecke correspondences, the tower has a Weil descent datum over EE, and there is a compatible system of étale and partially proper period maps

πK:MK→FℓG,μwa\pi_K:\mathcal{M}_K\rightarrow\mathscr{F}\ell_{G,\mu}^{wa}

that are equivariant for Jb(Qp)J_b(\mathbb{Q}_p). This conjecture predicts the existence and basic structure of local Shimura varieties, including their symmetries, descent, and period maps. The source further notes a more precise expected description of the image of the period maps, but that refinement is separate from the stated tower conjecture.

References

Primary source

Xu Shen, “On some generalized Rapoport-Zink spaces”, arXiv:1611.08977 (2019).

Progress summary

Refreshed
Open

The general theory predicted in 2014 has been built in important families, but no public source found here proves the full conjecture.

Rapoport and Viehmann formulated the conjecture in 2014 as a general existence theory for local Shimura varieties, including their symmetries, descent, and period maps. They explicitly said that the construction was unknown in the most general case.

Known results

  • Unramified Hodge-type data with p>2p>2: Rapoport–Zink towers were constructed (2013).
  • Rapoport–Zink spaces realize the conjecture in their setting, with the expected actions, descent, and period map (2016).
  • Local-shtuka constructions give local Shimura varieties for minuscule mumu in the stated framework (2017).
  • A 2023 exposition records important examples but does not claim a general proof.

Current status (as of September 2026): The full Rapoport–Viehmann conjecture remains open; substantial classes, including Rapoport–Zink and Hodge-type cases, are constructed, but no complete proof or counterexample was found.

Sources

Solutions 0

No solutions have been posted yet.