dfeo.tex
\magnification=\magstephalf
\input dfeo.mac
\input epsf
%%
\let\noarrow = t
\input eplain
\indexproofingtrue
%%
\newcount\refno\refno=1
\def\incr{\advance\refno by 1}
\edef\Berth{\number\refno}\incr
\edef\Bourb{\number\refno}\incr
\edef\deJO{\number\refno}\incr
\edef\Font{\number\refno}\incr
\edef\GorOo{\number\refno}\incr
\edef\Illus{\number\refno}\incr
\edef\KottIsoc{\number\refno}\incr
\edef\Kott{\number\refno}\incr
\edef\Kraft{\number\refno}\incr
\edef\GSAS{\number\refno}\incr
\edef\STPEL{\number\refno}\incr
\edef\FOAnn{\number\refno}\incr
\edef\FOTexel{\number\refno}\incr
\edef\FOTexelB{\number\refno}\incr
\edef\RapBourb{\number\refno}\incr
\edef\RR{\number\refno}\incr
\edef\Wedh{\number\refno}\incr

\centerline{{\sectitlefont A DIMENSION FORMULA FOR EKEDAHL-OORT STRATA}}
\Askip

\centerline{{\it by}\quad{\namefont Ben Moonen\footnote{*}{{\eightrm Research 
made possible by a fellowship of the Royal Netherlands Academy of Arts and 
Sciences}}\phantom{\quad{\it by}}}}
\Askip

\input Intro
\input Section1
\input Section2
\input Section3

\Askip\noindent
{\sectitlefont References}
\nobreak\bigskip\nobreak
{\eightpoint

\item{[\Berth]}
P.~Berthelot, {\it Th\'eorie de Dieudonn\'e sur un anneau de valuation 
parfait\/}, Ann.\ Scient.\ \'Ec.\ Norm.\ Sup.\ (4) {\bf 13} (1980), 225--268.

\item{[\Bourb]}
N.~Bourbaki, {\it Groupes et alg\`ebres de Lie, Chap.\ 4, 5, et 6\/}, Masson, 
Paris, 1981.

\item{[\deJO]}
A.J.~de Jong and F.~Oort, {\it Purity of the stratification by Newton polygons\/}, 
J.\ A.M.S.\ {\bf 13} (2000), 209--241.

\item{[\Font]}
J.-M.~Fontaine, {\it Groupes $p$-divisibles sur les corps locaux\/}, Ast\'erisque 
{\bf 47--48} (1977).  

\item{[\GorOo]}
E.~Goren and F.~Oort, {\it Stratifications of Hilbert modular varieties\/}, J.\ 
Alg.\ Geom.\ {\bf 9} (2000), 111--154.

\item{[\Illus]}
L.~Illusie, {\it D\'eformations de groupes de Barsotti-Tate (d'apr\`es 
A.~Grothendieck)\/}, in: S\'emi\-naire sur les pinceaux arithm\'etiques: la 
conjecture de Mordell (L.~Szpiro, ed.), Ast\'erisque {\bf 127} (1985), 151--198.

\item{[\KottIsoc]}
R.E.~Kottwitz, {\it Isocrystals with additional structure\/}, Compos.\ Math.\ 
{\bf 56} (1985), 201--220; {\it ---~\Romno 2\/}, Compos.\ Math.\ {\bf 109} (1997), 
255--339.

\item{[\Kott]}
R.E.~Kottwitz, {\it Points on some Shimura varieties over finite fields\/}, 
J.A.M.S.\ {\bf 5} (1992), 373--444.

\item{[\Kraft]}
H.~Kraft, {\it Kommutative algebraische $p$-Gruppen (mit Anwendungen auf 
$p$-divisible Gruppen und abelsche Variet\"aten)\/}, manuscript, Univ.\ Bonn, 
Sept.\ 1975, 86 pp. (Unpublished)

\item{[\GSAS]}
B.J.J.~Moonen, {\it Group schemes with additional structures and Weyl group 
cosets\/}, in: Moduli of Abelian Varieties (C.~Faber, G.~van der Geer, F.~Oort, 
eds.), Progr.\ Math.\ {\bf 195}, Birkh\"auser, Basel, 2001, pp.\ 255--298.

\item{[\STPEL]}
B.J.J.~Moonen, {\it Serre-Tate theory for moduli spaces of PEL type\/}, 
math.AG/0203288.

\item{[\FOAnn]}
F.~Oort, {\it Newton polygons and formal groups: conjectures by Manin and 
Grothendieck\/}, Ann.\ Math.\ {\bf 152} (2000), 183--206.

\item{[\FOTexel]}
F.~Oort, {\it A stratificiation of a moduli space of abelian varieties\/}, in:
Moduli of Abelian Varieties (C.~Faber, G.~van der Geer, F.~Oort, eds.), Progr.\ 
Math.\ {\bf 195}, Birkh\"auser, Basel, 2001, pp.\ 345--416.

\item{[\FOTexelB]}
F.~Oort, {\it Newton polygon strata in the moduli space of abelian varieties\/}, in:
Moduli of Abelian Varieties (C.~Faber, G.~van der Geer, F.~Oort, eds.), Progr.\ 
Math.\ {\bf 195}, Birkh\"auser, Basel, 2001, pp.\ 417--440.

\item{[\RapBourb]}
M.~Rapoport, {\it On the Newton stratification\/}, S\'em.\ Bourbaki, Mars 2002.

\item{[\RR]}
M.~Rapoport and M.~Richartz, {\it On the classification and specialization of 
$F$-isocrystals with additional structure\/}, Compos.\ Math.\ {\bf 103} (1996), 
153--181.

\item{[\Wedh]}
T.~Wedhorn, {\it The dimension of Oort strata of Shimura varieties of PEL-type\/}, 
in: Moduli of Abelian Varieties (C.~Faber, G.~van der Geer, F.~Oort, eds.), Progr.\ 
Math.\ {\bf 195}, Birkh\"auser, Basel, 2001, pp.\ 441--471.
\Bskip 

\noindent
Ben Moonen, University of Amsterdam, Korteweg-de Vries Institute for Mathematics, 
Plantage Muidergracht~24, 1018~TV Amsterdam, The Netherlands. 
Email: {\tt bmoonen@science.uva.nl}\par}
\bye  

      

 
