RÉSUMÉ

The talk is dedicated to finite commutative group schemes and their applications to the study of good reduction of Abelian varieties. The Cartier-Dieudonne modules for finite commutative group schemes (defined by Oort) are used. Several properties of Cartier-Oort modules are proved. In particular, the complete classification of finite commutative group schemes in terms of Cartier-Oort modules is given; the computation of $Ext1$ for group schemes is done. The main applications are the properties of the generic fiber functor and a complete answer to the question of N. Katz (given by B. Conrad in the case $e\leq p-1$). The possibilities of a further development of the theory are discussed.

WWW page design par Thomas Papanikolaou & Christine Bachoc