3 citations · 4 across the 2 of their papers we have counts for
8 papers
Cocharacter-closure and spherical buildings
Michael Bate, Sebastian Herpel, Benjamin Martin +1
Let be a field, let be a reductive -group and an affine -variety on which acts. In this note we continue our study of the notion of cocharacter-closed -…
Cocharacter-closure and the rational Hilbert-Mumford Theorem
Michael Bate, Sebastian Herpel, Benjamin Martin +1
For a field k, let G be a reductive k-group and V an affine k-variety on which G acts. Using the notion of cocharacter-closed G(k)-orbits in V, we prove a rational version of the c…
Maximal subalgebras of Cartan type in the exceptional Lie algebras
Sebastian Herpel, David I. Stewart
In this paper we initiate the study of the maximal subalgebras of exceptional simple classical Lie algebras \g over algebraically closed fields k of positive characteristic p, such…
On the smoothness of normalisers and the subalgebra structure of modular Lie algebras
Sebastian Herpel, David I. Stewart
We provide results on the smoothness of normalisers in connected reductive algebraic groups over fields of positive characteristic . Specifically we we give bounds on $p…
G-complete reducibility in non-connected groups
Michael Bate, Sebastian Herpel, Benjamin Martin +1
In this paper we present an algorithm for determining whether a subgroup H of a non-connected reductive group G is G-completely reducible. The algorithm consists of a series of red…
Complete reducibility and Steinberg endomorphisms
Sebastian Herpel, Gerhard Roehrle
Let G be a connected reductive algebraic group defined over an algebraically closed field of positive characteristic. We study a generalization of the notion of G-complete reducibi…
-complete reducibility and semisimple modules
M. Bate, S. Herpel, B. Martin +1
Let be a connected reductive algebraic group defined over an algebraically closed field % of characteristic . Our first aim in this note is to give concise and unifor…
On the Smoothness of Centralizers in Reductive Groups
Sebastian Herpel
Let G be a connected reductive algebraic group over an algebraically closed field k. In a recent paper, Bate, Martin, Röhrle and Tange show that every (smooth) subgroup of G is sep…