field is reductive if it has a representation that has a finite kernel and is a direct sum of irreducible representations. Reductive groups include some...
56 KB (8,018 words) - 09:30, 15 April 2025
reductive groups, but over non-perfect fields Jacques Tits found some examples of pseudo-reductive groups that are not reductive. A pseudo-reductive k-group...
8 KB (1,102 words) - 17:57, 7 May 2025
require reductive groups to be connected.) A semisimple group is reductive. A group G over an arbitrary field k is called semisimple or reductive if G k...
41 KB (6,000 words) - 12:59, 4 October 2024
a quasi-split group over a field is a reductive group with a Borel subgroup defined over the field. Simply connected quasi-split groups over a field correspond...
1 KB (153 words) - 17:15, 17 May 2023
Reductive amination (also known as reductive alkylation) is a form of amination that converts a carbonyl group to an amine via an intermediate imine. The...
25 KB (2,481 words) - 14:26, 22 May 2025
connected reductive algebraic group over the algebraically closed field K, then its Langlands dual group LG is the complex connected reductive group whose...
7 KB (936 words) - 04:56, 26 February 2024
algebraic group is (essentially) a semidirect product of a unipotent group (its unipotent radical) with a reductive group. In turn, a reductive group is decomposed...
16 KB (2,244 words) - 15:28, 15 May 2025
the unipotent radical, it serves to define reductive groups. Reductive group Unipotent group "Radical of a group", Encyclopaedia of Mathematics v t e...
1 KB (148 words) - 12:23, 13 August 2023
Langlands program (category Representation theory of Lie groups)
for one semisimple (or reductive) Lie group, can be done for all. Therefore, once the role of some low-dimensional Lie groups such as GL(2) in the theory...
21 KB (2,351 words) - 22:52, 31 May 2025
collection of (isomorphism classes of) irreducible representations of a reductive group over a local field, that are L-indistinguishable, meaning they have...
4 KB (526 words) - 14:10, 23 April 2024
Gelfand pair (category Representation theory of groups)
are (G, K), where G is a reductive Lie group and K is a maximal compact subgroup. When G is a locally compact topological group and K is a compact subgroup...
31 KB (4,028 words) - 20:21, 18 May 2025
unipotent representation of a reductive group is a representation that has some similarities with unipotent conjugacy classes of groups. Informally, Langlands...
3 KB (374 words) - 18:57, 26 January 2024
constructing representations of a reductive group from representations of its parabolic subgroups. If G is a reductive algebraic group and P = M A N {\displaystyle...
3 KB (389 words) - 21:06, 10 January 2024
linearly reductive groups acting on regular rings are Cohen–Macaulay. In other words, if V is a rational representation of a linearly reductive group G over...
2 KB (280 words) - 08:19, 1 May 2021
Iwahori subgroup (redirect from Iwahori group)
subgroup of a reductive algebraic group over a nonarchimedean local field that is analogous to a Borel subgroup of an algebraic group. A parahoric subgroup...
7 KB (805 words) - 20:17, 26 May 2025
complex reductive group. If the complex vector space is given a norm that is invariant under a maximal compact subgroup of the reductive group, then the...
2 KB (181 words) - 02:15, 20 July 2023
In mathematics, a permutation group is a group G whose elements are permutations of a given set M and whose group operation is the composition of permutations...
23 KB (3,367 words) - 22:43, 24 November 2024
in group theory, the phrase group of Lie type usually refers to finite groups that are closely related to the group of rational points of a reductive linear...
22 KB (2,985 words) - 04:28, 23 November 2024
known as group theory, the monster group M (also known as the Fischer–Griess monster, or the friendly giant) is the largest sporadic simple group; it has...
38 KB (3,096 words) - 03:28, 2 June 2025
Haboush's theorem (category Representation theory of algebraic groups)
ISBN 978-3-540-07686-5, MR 0444786 Haboush, W. J. (1975), "Reductive groups are geometrically reductive", Annals of Mathematics, 102 (1): 67–83, doi:10.2307/1970974...
8 KB (1,094 words) - 02:32, 29 June 2023
In mathematics, the Klein four-group is an abelian group with four elements, in which each element is self-inverse (composing it with itself produces...
10 KB (1,384 words) - 13:00, 16 February 2025
specifically in the field of group theory, a solvable group or soluble group is a group that can be constructed from abelian groups using extensions. Equivalently...
18 KB (3,033 words) - 00:00, 23 April 2025
The Poincaré group, named after Henri Poincaré (1905), was first defined by Hermann Minkowski (1908) as the isometry group of Minkowski spacetime. It...
15 KB (2,173 words) - 11:07, 14 November 2024
In abstract algebra, group theory studies the algebraic structures known as groups. The concept of a group is central to abstract algebra: other well-known...
39 KB (5,086 words) - 18:26, 11 April 2025
similar result holds for any PSL(2, q2), q odd. Let G now be a connected reductive group over an algebraically closed field. Then any two Borel subgroups are...
11 KB (1,123 words) - 23:09, 7 April 2025
mathematics, the name symplectic group can refer to two different, but closely related, collections of mathematical groups, denoted Sp(2n, F) and Sp(n) for...
22 KB (3,109 words) - 10:15, 24 April 2025
In geometry and group theory, a lattice in the real coordinate space R n {\displaystyle \mathbb {R} ^{n}} is an infinite set of points in this space with...
17 KB (2,289 words) - 23:00, 6 May 2025
finite group is the number of its elements. If a group is not finite, one says that its order is infinite. The order of an element of a group (also called...
11 KB (1,337 words) - 08:48, 12 July 2024
Moy–Prasad filtration (category Representation theory of algebraic groups)
mathematics, the Moy–Prasad filtration is a family of filtrations of p-adic reductive groups and their Lie algebras, named after Allen Moy and Gopal Prasad. The...
21 KB (4,086 words) - 02:18, 28 May 2025
representation of a reductive algebraic group such as GL2 over a finite or local or global field on a space of functions on the group. It is named after...
5 KB (668 words) - 01:59, 14 November 2024