A dimension formula for Ekedahl-Oort strata

Abstract

We study the Ekedahl-Oort stratification on moduli spaces of PEL type. The strata are indexed by cosets in a Weyl group. The main result of this paper is that the dimension of a stratum equals the length of the corresponding Weyl group element. We also discuss some explicit examples.

Plain TeX, 23 pages, 5 postscript figures; this is a completely revised version of results that were earlier included in math.AG/0203288