• 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
  • Thumbnail for Lie algebra representation
    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
  • Thumbnail for Representation theory
    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
  • Thumbnail for Semisimple Lie algebra
    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
  • Thumbnail for Reductive 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
  • Thumbnail for Group representation
    construct any general representation theory, but specific special cases have been studied, sometimes using ad hoc techniques. The semisimple Lie groups have...
    15 KB (2,245 words) - 02:55, 11 May 2025
  • 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
  • Thumbnail for Representation theory of semisimple Lie algebras
    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
  • Thumbnail for Representation theory of the Poincaré group
    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
  • Thumbnail for Cartan subalgebra
    If in addition g {\displaystyle {\mathfrak {g}}} is semisimple, then the adjoint representation presents g {\displaystyle {\mathfrak {g}}} as a linear...
    15 KB (2,053 words) - 11:13, 22 February 2025
  • 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...
    19 KB (3,369 words) - 19:06, 2 December 2024
  • element is semisimple if its image under the adjoint representation is semisimple; see Semisimple Lie algebra#Jordan decomposition. This disambiguation...
    457 bytes (95 words) - 06:54, 13 August 2022
  • Thumbnail for Adjoint representation
    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
  • Thumbnail for Representation of a Lie group
    certain types of Lie groups, namely compact and semisimple groups, every finite-dimensional representation decomposes as a direct sum of irreducible representations...
    34 KB (5,246 words) - 08:31, 14 January 2025
  • 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
  • Thumbnail for Tensor
    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
  • }(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
  • Thumbnail for Lie algebra
    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
  • Thumbnail for Representation theory of the Lorentz group
    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