English

On the Bruhat-Tits stratification for GU(2,2) type Rapoport-Zink space: unramified case

Number Theory 2019-09-26 v2

Abstract

In this note we study the supersingular locus of the GU(2,2) Shimura variety modulo a prime which is unramified in the imaginary quadratic extension. The supersingular locus of this Shimura variety can be related to the basic Rapoport-Zink space whose special fibre is described by the Bruhat-Tits stratification. The description for this supersingular locus in the case where the prime is inert in imaginary quadratic field is already known to Howard and Pappas by exploiting the exceptional isomorphism. Our method is more direct without using the exceptional isomorphism.

Keywords

Cite

@article{arxiv.1909.10902,
  title  = {On the Bruhat-Tits stratification for GU(2,2) type Rapoport-Zink space: unramified case},
  author = {Haining Wang},
  journal= {arXiv preprint arXiv:1909.10902},
  year   = {2019}
}

Comments

arXiv admin note: text overlap with arXiv:1907.05999