Abstract
We determine the set of connected components of closed affine Deligne–Lusztig varieties for special maximal compact subgroups of split connected reductive groups. We show that there is a transitive group action on this set. Thus such an affine Deligne–Lusztig variety has isolated points if and only if its dimension is 0. We also obtain a description of the set of these varieties that are zero-dimensional.
Similar content being viewed by others
Refererences
Görtz U., Haines Th.J., Kottwitz R.E. and Reuman D.C. (2006). Dimensions of some affine Deligne–Lusztig varieties. Ann. Sci. École Norm. Sup. 39: 467–511
Kottwitz R.E. (1985). Isocrystals with additional structure. Comp. Math. 56: 201–220
Kottwitz R.E. (1997). Isocrystals with additional structure II. Comp. Math. 109: 255–339
Kottwitz R.E. (2003). On the Hodge–Newton decomposition for split groups. IMRN 26: 1433–1447
Kottwitz R.E. and Rapoport M. (2003). On the existence of F-crystals. Comment. Math. Helv. 78: 153–184
Mantovan, E., Viehmann, E.: On the Hodge–Newton filtration for p-divisible \({\mathcal{O}}\) -modules (in preparation)
Mierendorff, E.: On affine Deligne–Lusztig varieties for GL n . Dissertation, Bonn (2005) http://www.hss.ulb.uni-bonn.de/diss_online/math_nat_fak/2005/mierendorff_eva/
Rapoport M. (2000). A positivity property of the Satake isomorphism. Manuscripta Math. 101(2): 153–166
Viehmann E. (2006). The dimension of some affine Deligne–Lusztig varieties. Ann. Sci. École Norm. Sup. 39: 513–526
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Viehmann, E. Connected components of closed affine Deligne–Lusztig varieties. Math. Ann. 340, 315–333 (2008). https://doi.org/10.1007/s00208-007-0153-8
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00208-007-0153-8