English

Counting Points on Igusa Varieties of Hodge Type

Number Theory 2022-03-04 v1

Abstract

Igusa varieties are algebraic varieties that arise in the study of special fibers of Shimura varieties, and have demonstrated many applications in the Langlands program via a Langlands-Kottwitz style point-counting formula due to Shin in the case of PEL type. In this paper we formulate and prove an analogue of the Langlands-Rapoport conjecture for Igusa varieties of Hodge type, building off the work of Kisin in the case of Shimura varieties. We then use this description of the points to derive a point-counting formula for Igusa varieties of Hodge type, generalizing the fomula in PEL type of Shin, by drawing on the techniques of Kisin-Shin-Zhu.

Keywords

Cite

@article{arxiv.2203.01448,
  title  = {Counting Points on Igusa Varieties of Hodge Type},
  author = {Sander Mack-Crane},
  journal= {arXiv preprint arXiv:2203.01448},
  year   = {2022}
}