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On the Bruhat–Tits stratification of a quaternionic unitary Rapoport–Zink space

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Abstract

In this article we study the special fiber of the Rapoport–Zink space attached to a quaternionic unitary group. The special fiber is described using the so called Bruhat–Tits stratification and is intimately related to the Bruhat–Tits building of a split symplectic group. As an application we describe the supersingular locus of the related Shimura variety.

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References

  1. Berthelot, P., Breen, L., Messing, W.: Messing, Théorie de Dieudonné Cristalline. II: Lecture Notes in Mathematics, vol. 930. Springer, Berlin (1982)

    Book  Google Scholar 

  2. Bhatt, B., Scholze, P.: Projectivity of the Witt vector affine Grassmannian. Invent. Math. 209(2), 329–423 (2017)

    Article  MathSciNet  Google Scholar 

  3. Cho, S.: The basic locus of the unitary Shimura variety with parahoric level structure and special cycles. arXiv:1807.09997 (Preprint) (2018)

  4. Chen, M.-F., Viehmann, E.: Affine Deligne–Lusztig varieties and the action of \(J\). J. Algebraic Geom. 27(2), 273–304 (2018)

    Article  MathSciNet  Google Scholar 

  5. Deligne, P., Lusztig, G.: Representations of reductive groups over finite fields. Ann. Math. (2) 103(1), 103–161 (1976)

    Article  MathSciNet  Google Scholar 

  6. Görtz, U., He, X.-H.: Basic loci of Coxeter type in Shimura varieties. Camb. J. Math. 3(3), 323–353 (2015)

    Article  MathSciNet  Google Scholar 

  7. Görtz, U., He, X.-H.: Erratum to: Basic loci in Shimura varieties of Coxeter type. Camb. J. Math. 3(3), 323–353 (2018)

    Article  Google Scholar 

  8. Görtz, U., He, X.-H., Nie, S.-A.: Fully Hodge-Newton decomposable Shimura varieties. arXiv:1610.05381 (Preprint) (2016)

  9. Görtz, U.: Stratifications of affine Deligne–Lusztig varieties. arXiv:1802.02225 (Preprint) (2018)

  10. Helm, D.: Towards a geometric Jacquet–Langlands correspondence for unitary Shimura varieties. Duke Math. J. 155(3), 483–518 (2010)

    Article  MathSciNet  Google Scholar 

  11. Howard, B., Pappas, G.: On the supersingular locus of the \({\rm GU}(2,2)\) Shimura variety. Algebra Number Theory 8(7), 1659–1699 (2014)

    Article  MathSciNet  Google Scholar 

  12. Howard, B., Pappas, G.: Rapoport–Zink spaces for spinor groups. Compos. Math. 153(5), 1050–1118 (2017)

    Article  MathSciNet  Google Scholar 

  13. Helm, D., Tian, Y.-C., Xiao, L.: Tate cycles on some unitary Shimura varieties mod \(p\). Algebra Number Theory 11(10), 2213–2288 (2017)

    Article  MathSciNet  Google Scholar 

  14. Katsura, T., Oort, F.: Families of supersingular abelian surfaces. Compos. Math. 63(2), 107–167 (1987)

    MathSciNet  MATH  Google Scholar 

  15. Kottwitz, R.: Points on some Shimura varieties over finite fields. J. Am. Math. Soc. 2, 373–444 (1985)

    MathSciNet  MATH  Google Scholar 

  16. Kottwitz, R.: Isocrystals with additional structure. II. Compos. Math. 109(3), 225–339 (1997)

    Article  MathSciNet  Google Scholar 

  17. Kudla, S., Rapoport, M.: Cycles on Siegel threefolds and derivatives of Eisenstein series. Ann. Sci. École Norm. Sup. (4) 33(5), 695–756 (2000)

    Article  MathSciNet  Google Scholar 

  18. Kottwitz, R.: Isocrystals with additional structure. Compos. Math. 56(2), 201–220 (1985)

    MathSciNet  MATH  Google Scholar 

  19. Madapusi Pera, K.: Integral canonical models for spin Shimura varieties. Compos. Math. 152(4), 769–824 (2016)

    Article  MathSciNet  Google Scholar 

  20. Norman, P., Oort, F.: Moduli of abelian varieties. Ann. Math. (2) 112(3), 413–439 (1980)

    Article  MathSciNet  Google Scholar 

  21. Oki, Y.: On the supersingular loci of Shimura varieties for quaternion unitary groups of degree 2. Master Thesis, The University of Tokyo. arXiv:1907.07026

  22. Rapoport, M.: A guide to the reduction modulo \(p\) of Shimura varieties. Automorphic forms. I. Astérisque 298, 271–318 (2005)

    MATH  Google Scholar 

  23. Rapoport, M., Zink, T.: Period Spaces for \(p\)-Divisible Droups, Annals of Mathematics Studies, vol. 141, p. xxii+324. Princeton University Press, Princeton (1996)

    Google Scholar 

  24. Rapoport, M., Terstiege, U., Wilson, S.: The supersingular locus of the Shimura variety for \({\rm GU}(1, n-1)\) over a ramified prime. Math. Z. 276(3–4), 1165–1188 (2014)

    Article  MathSciNet  Google Scholar 

  25. Tits, J.: Reductive Groups Over Local Fields, Automorphic Forms, Representations and L-functions (Proc. Sympos. Pure Math., Oregon State Univ., Corvallis, Ore., 1977). American Mathematical Society, Providence (1979)

    Google Scholar 

  26. Van Hoften, P.: A geometric Jacquet–Langlands correspondence for paramodular Siegel threefolds. arXiv:1906.04008 (preprint) (2019)

  27. Vollaard, I.: The supersingular locus of the Shimura variety for \({\rm GU}(1, s)\). Can. J. Math. 62(3), 668–720 (2010)

    Article  MathSciNet  Google Scholar 

  28. Vollaard, I., Wedhorn, T.: The supersingular locus of the Shimura variety of \({\rm GU}(1, n-1)\) II. Invent. Math. 184(3), 591–627 (2011)

    Article  MathSciNet  Google Scholar 

  29. Wang, H.-N.: On the Bruhat–Tits stratification for GU(2,2) type Rapoport–Zink space: unramified case. arXiv:1909.10902 (preprint) (2019)

  30. Wang, H-.N.: On a quaternionic unitary Rapoport–Zink space with parahoric level structure. arXiv:1909.12263 (preprint) (2019)

  31. Wang, H.-N.: Level lowering for GSp(4) and vanishing cycles on Siegel threefold. arXiv:1910.07569 (preprint) (2019)

  32. Wu, H-F.: The supersingular locus of unitary Shimura varieties with exotic good reduction. PhD thesis, University of Duisburg-Essen. arXiv:1609.08775 (2016)

  33. Yu, C.-F.: The supersingular loci and mass formulas on Siegel modular varieties. Doc. Math. 11, 449–468 (2006)

    MathSciNet  MATH  Google Scholar 

  34. Yu, C.-F.: Geometry of the Siegel modular threefold with paramodular level structure. Proc. Am. Math. Soc. 139, 3181–3190 (2011)

    Article  MathSciNet  Google Scholar 

  35. Zink, T.: Windows for Displays of \(p\)-Divisible Groups, Moduli of Abelian Varieties (Texel Island, 1999) Progr. Math, vol. 196, pp. 491–518. Birkhäuser, Basel (2001)

    Google Scholar 

  36. Zhu, X.-W.: Affine Grassmannians and the geometric Satake in mixed characteristic. Ann. Math. (2) 185(2), 403–492 (2017)

    Article  MathSciNet  Google Scholar 

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Acknowledgements

The author would like to thank Henri Darmon for supporting his postdoctoral studies. He would like to thank Liang Xiao for many helpful conversations regarding to Shimura varieties and beyond. He is grateful to Ulrich Görtz for all the help and his comments on this article. He is inspired by reading many works of Chia-Fu Yu on Siegel modular varieties. He also would like to thank Ben Howard, Eyal Goren, Yichao Tian, Xu Shen and Benedict Gross for valuable discussions related to this article. He would like to thank the referees for carefully reading the article and pointing out all the corrections. While this article is being reviewed, Yasuhiro Oki obtained similar results about the supersingular locus of the quaternionic unitary Shimura variety independently. His method is completely different. He exploited the exceptional isomorphisms between the group \(\mathrm {GU}_{B}(2)\) and the non-split \(\mathrm {GSpin}(3,2)\). Then he embedded the non-split \(\mathrm {GSpin}(3,2)\) in the split \(\mathrm {GSpin}(4,2)\). This allows him to use the results of Howard-Pappas [11] mentioned before. We would like to thank Yoichi Mieda for sending Oki’s work to us.

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Correspondence to Haining Wang.

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Communicated by Wei Zhang.

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Wang, H. On the Bruhat–Tits stratification of a quaternionic unitary Rapoport–Zink space. Math. Ann. 376, 1107–1144 (2020). https://doi.org/10.1007/s00208-019-01938-w

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