Carter subgroups of groups of finite Morley rank

Presented by:
E Jaligot [Paris 7]
Date:
Thursday 10th March 2005 - 11:30 to 12:30
Venue:
INI Seminar Room 2
Abstract:

Most transcendence proofs rely on a collection of statements of a purely geometric nature: the zero estimates" (or vanishing lemmas"), which ensure injectivity (or surjectivity) of an evaluation map on sections of a vector bundle at zero-dimensional subschemes of the base. We shall present (and time permitting, prove) them in a unified way, covering two of the main areas of transcendence: periods of one-motives (Baker-Wustholz theory), and values of solutions of differential equations (Siegel-Shidlovsky theorem).

A new proof of the latter theorem will also be discussed, as well as a $q$-difference analogue of the corresponding vanishing lemma".

In each case, the vanishing lemmas exhibit a geometric obstruction which is the key not only to the trancendence results themselves, but also to their conjectural generalizations (Schanuel, Grothendieck, Andr\'e).

Reference:

D. Bertrand: Le th\'eor\`eme de Siegel-Shidlovsky revisit\'e, Pr\'epublication de l'Institut de Math\'ematiques de Jussieu, No 390, Mai 2004.