activity
20152024
most citedOn Non-Generic Finite Subgroups of Exceptional Algebraic Groups

8 citations · 10 across the 11 of their papers we have counts for

collaborators

14 papers

math.RT2024

-complete reducibility and saturation

Michael Bate, Sören Böhm, Alastair Litterick +2

Let be connected reductive linear algebraic groups defined over an algebraically closed field of characteristic . In our first main theorem we show that if a…

cs.DM2023★ 1 cited

Condorcet Domains of Degree at most Seven

Dolica Akello-Egwell, Charles Leedham-Green, Alastair Litterick +2

In this paper we give the first explicit enumeration of all maximal Condorcet domains on alternatives. This has been accomplished by developing a new algorithm for constr…

math.GR2023★ 1 cited

Complete reducibility in bad characteristic

Alastair J. Litterick, Adam R. Thomas

Let be a simple algebraic group of exceptional type over an algebraically closed field of characteristic . This paper continues a long-standing effort to classify the co…

math.GR2023

Elementary abelian subgroups: from algebraic groups to finite groups

Jianbei An, Heiko Dietrich, Alastair J. Litterick

We describe a new approach for classifying conjugacy classes of elementary abelian subgroups in simple algebraic groups over an algebraically closed field, and understanding the no…

math.GR2022

Complete reducibility and subgroups of exceptional algebraic groups

Alastair J. Litterick, David I. Stewart, Adam R. Thomas

This survey article has two components. The first part gives a gentle introduction to Serre's notion of -complete reducibility, where is a connected reductive algebraic grou…

math.GR2020

Complete reducibility of subgroups of reductive algebraic groups over nonperfect fields IV: An example

Falk Bannuscher, Alastair Litterick, Tomohiro Uchiyama

Let be a nonperfect separably closed field. Let be a connected reductive algebraic group defined over . We study rationality problems for Serre's notion of complete redu…

math.GR2020

Complete reducibility: Variations on a theme of Serre

Maike Gruchot, Alastair Litterick, Gerhard Roehrle

In this note, we unify and extend various concepts in the area of -complete reducibility, where is a reductive algebraic group. By results of Serre and Bate--Martin--Röhrle,…

math.GR2019

Rigid representations of triangle groups

Alastair Litterick, Benjamin Martin

We prove a generalization of a conjecture of C. Marion on generation properties of finite groups of Lie type, by considering geometric properties of an appropriate representation v…

math.GR2018

Relative complete reducibility and normalised subgroups

Maike Gruchot, Alastair Litterick, Gerhard Roehrle

We study a relative variant of Serre's notion of -complete reducibility for a reductive algebraic group . We let be a reductive subgroup of , and consider subgroups of…

math.GR2018

Further Rigid Triples of Classes in

Matthew Conder, Alastair Litterick

We establish the existence of two rigid triples of conjugacy classes in the algebraic group in characteristic , complementing results of the second author with Liebeck a…

math.GR2018

Reducible subgroups of exceptional algebraic groups

Alastair J. Litterick, Adam R. Thomas

Let be a simple algebraic group over an algebraically closed field. A closed subgroup of is called -completely reducible (-cr) if, whenever is contained in a…

math.GR2017

On finite simple images of triangle groups

Sebastian Jambor, Alastair Litterick, Claude Marion

For a simple algebraic group G in characteristic p, a triple (a,b,c) of positive integers is said to be rigid for G if the dimensions of the subvarieties of G of elements of order…

math.GR2015★ 8 cited

On Non-Generic Finite Subgroups of Exceptional Algebraic Groups

Alastair J. Litterick

The study of finite subgroups of a simple algebraic group reduces in a sense to those which are almost simple. If an almost simple subgroup of has a socle which is not isom…

math.GR2015

Complete Reducibility in Good Characteristic

Alastair J. Litterick, Adam R. Thomas

Let be a simple algebraic group of exceptional type, over an algebraically closed field of characteristic . A closed subgroup of is called -completely reduc…