Abstract
Let G be a simple algebraic group of exceptional type, over analgebraically closed field of characteristic p ≥ 0. A closed subgroup H of G is called G-completely reducible (G-cr) if whenever H is containedin a parabolic subgroup P of G, it is contained in a Levi subgroup of P. In this paper we determine the G-conjugacy classes of non-G-cr simpleconnected subgroups of G when p is good for G. For each such subgroup X, we determine the action of X on the adjoint module L(G) and theconnected centraliser of X in G. As a consequence we classify all non-G-cr connected reductive subgroups of G, and determine their connected centralisers. We also classify the subgroups of G which are maximal amongconnected reductive subgroups, but not maximal among all connected subgroups.
Original language | English |
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Pages (from-to) | 5279-5340 |
Number of pages | 62 |
Journal | Transactions of the American Mathematical Society |
Volume | 370 |
Early online date | 17 Apr 2018 |
DOIs | |
Publication status | E-pub ahead of print - 17 Apr 2018 |