EN
CONTENTS
Introduction............................................................................................................................................5
1. Cohen schemes.................................................................................................................................7
2. Projective abelian Hopf algebras......................................................................................................11
3. The structure of groups $Hom_{ℋ ₁}(^mP,^nP)$..............................................................................17
4. Endomorphism rings of $^nP$..........................................................................................................27
5. The $End_{ℋ ₁}(^nP) - End_{ℋ ₁}(^mP)$-bimodule structure of $Hom_{ℋ ₁}(^mP,^nP)$................31
References..........................................................................................................................................42