specifically in representation theory, a semisimple representation (also called a completely reducible representation) is a linear representation of a group...
24 KB (4,081 words) - 03:48, 19 May 2025
said to be reductive if the adjoint representation is semisimple. Certainly, every (finite-dimensional) semisimple Lie algebra g {\displaystyle {\mathfrak...
28 KB (4,312 words) - 17:24, 28 November 2024
representations of semisimple Lie algebras are completely understood, after work of Élie Cartan. A representation of a semisimple Lie algebra 𝖌 is analysed...
56 KB (7,269 words) - 14:03, 18 May 2025
of the same notion, see Semisimple representation. A module over a (not necessarily commutative) ring is said to be semisimple (or completely reducible)...
10 KB (1,249 words) - 15:50, 18 September 2024
Semi-simplicity (redirect from Semisimple)
complete reducibility says a finite-dimensional representation of a semisimple compact Lie group is semisimple. A square matrix (in other words a linear operator...
13 KB (1,867 words) - 10:13, 18 February 2024
In mathematics, a Lie algebra is semisimple if it is a direct sum of simple Lie algebras. (A simple Lie algebra is a non-abelian Lie algebra without any...
41 KB (5,743 words) - 05:34, 4 March 2025
Reductive group (redirect from Semisimple group)
connected group G {\displaystyle G} admitting a faithful semisimple representation which remains semisimple over its algebraic closure k a l {\displaystyle k^{al}}...
56 KB (8,018 words) - 09:30, 15 April 2025
construct any general representation theory, but specific special cases have been studied, sometimes using ad hoc techniques. The semisimple Lie groups have...
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linear operator on V, then V is a semisimple representation of T. Equivalently, a linear operator is semisimple if its minimal polynomial is a product of...
2 KB (291 words) - 16:24, 6 December 2024
In mathematics, the representation theory of semisimple Lie algebras is one of the crowning achievements of the theory of Lie groups and Lie algebras...
28 KB (4,247 words) - 03:57, 25 May 2025
In mathematics, a tempered representation of a linear semisimple Lie group is a representation that has a basis whose matrix coefficients lie in the Lp...
11 KB (1,430 words) - 18:45, 26 January 2024
classical Lie group is a fundamental representation. Any finite-dimensional irreducible representation of a semisimple Lie group or Lie algebra can be constructed...
3 KB (475 words) - 08:23, 28 August 2022
finite-dimensional representations of semisimple Lie algebras Fulton, William; Harris, Joe (1991). Representation theory. A first course. Graduate Texts...
22 KB (3,368 words) - 17:09, 14 April 2025
representation theory of a Lie group that is neither a compact group nor a semisimple group. It is fundamental in theoretical physics. In a physical theory...
5 KB (584 words) - 13:23, 26 May 2024
If in addition g {\displaystyle {\mathfrak {g}}} is semisimple, then the adjoint representation presents g {\displaystyle {\mathfrak {g}}} as a linear...
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of the representation theory of Lie groups, the study of representations of SU(2) is fundamental to the study of representations of semisimple Lie groups...
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element is semisimple if its image under the adjoint representation is semisimple; see Semisimple Lie algebra#Jordan decomposition. This disambiguation...
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adjoint representation of G: Int ( g ) = Ad ( G ) {\displaystyle \operatorname {Int} ({\mathfrak {g}})=\operatorname {Ad} (G)} . If G is semisimple, the...
21 KB (3,517 words) - 18:29, 23 March 2025
certain types of Lie groups, namely compact and semisimple groups, every finite-dimensional representation decomposes as a direct sum of irreducible representations...
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Deligne–Lusztig theory (category Representation theory)
can associate a semisimple character (corresponding to some semisimple element s of the dual group), and a unipotent representation of the centralizer...
28 KB (4,066 words) - 01:55, 18 January 2025
of K does divide |G|, is harder mainly because with K[G] not semisimple, a representation can fail to be irreducible without splitting as a direct sum...
10 KB (1,557 words) - 00:17, 16 April 2025
non-rational, but are still semisimple representations. A further class of transformations come from the logarithmic representation of the general linear group...
69 KB (9,357 words) - 21:16, 23 May 2025
coadjoint representation is the dual representation of an adjoint representation. complete “completely reducible" is another term for "semisimple". complex...
34 KB (5,011 words) - 21:43, 4 September 2024
of G is divisible by the characteristic of K, the group algebra is not semisimple, hence has non-zero Jacobson radical. In that case, there are finite-dimensional...
18 KB (2,613 words) - 08:46, 23 November 2024
Character theory (redirect from Character of a representation of a group)
}(e^{X})} . Suppose now that g {\displaystyle {\mathfrak {g}}} is a complex semisimple Lie algebra with Cartan subalgebra h {\displaystyle {\mathfrak {h}}} ...
24 KB (3,521 words) - 06:38, 16 December 2024
Lie algebra (section Simple and semisimple)
characteristic zero, every finite-dimensional representation of a semisimple Lie algebra is semisimple (that is, a direct sum of irreducible representations)...
61 KB (10,477 words) - 22:23, 2 April 2025
is semisimple, then every element of g {\displaystyle {\mathfrak {g}}} is a linear combination of commutators, in which case every representation of g...
25 KB (4,247 words) - 01:56, 23 May 2025
Weyl's theorem on complete reducibility (category Theorems in representation theory)
representations (specifically in the representation theory of semisimple Lie algebras). Let g {\displaystyle {\mathfrak {g}}} be a semisimple Lie algebra over a field...
15 KB (2,465 words) - 22:28, 4 February 2025
theory of semisimple Lie algebras (or the closely related representation theory of compact Lie groups), the weights of the dual representation are the negatives...
10 KB (1,699 words) - 19:20, 8 October 2024
Lorentz group is deduced using the general framework of the representation theory of semisimple Lie algebras. The finite-dimensional representations of the...
150 KB (19,763 words) - 06:35, 10 May 2025