semisimple element
71Crystal base — In algebra, a crystal base or canonical base is a base of a representation, such that generators of a quantum group or semisimple Lie algebra have a particularly simple action on it. Crystal bases were introduced by Kashiwara (1990) and… …
72Jacobson radical — In ring theory, a branch of abstract algebra, the Jacobson radical of a ring R is an ideal of R which contains those elements of R which in a sense are close to zero . DefinitionThe Jacobson radical is denoted by J( R ) and can be defined in the… …
73Cartan connection — In the mathematical field of differential geometry, a Cartan connection is a flexible generalization of the notion of an affine connection. It may also be regarded as a specialization of the general concept of a principal connection, in which the …
74Hecke algebra — is the common name of several related types of associative rings in algebra and representation theory. The most familiar of these is the Hecke algebra of a Coxeter group , also known as Iwahori Hecke algebra, which is a one parameter deformation… …
75Haboush's theorem — In mathematics Haboush s theorem, often still referred to as the Mumford conjecture, states that for any semisimple algebraic group G over a field K , and for any linear representation ρ of G on a K vector space V , given v ne;0 in V that is… …
76ADE classification — The simply laced Dynkin diagrams classify diverse mathematical objects. In mathematics, the ADE classification (originally A D E classifications) is the complete list of simply laced Dynkin diagrams or other mathematical objects satisfying… …
77Poincaré–Birkhoff–Witt theorem — In the theory of Lie algebras, the Poincaré–Birkhoff–Witt theorem (Poincaré (1900), G. D. Birkhoff (1937), Witt (1937); frequently contracted to PBW theorem) is a result giving an explicit description of the universal enveloping algebra of a Lie… …
78Exponential map — In differential geometry, the exponential map is a generalization of the ordinary exponential function of mathematical analysis to all differentiable manifolds with an affine connection. Two important special cases of this are the exponential map …
79Weyl group — In mathematics, in particular the theory of Lie algebras, the Weyl group of a root system Phi; is a subgroup of the isometry group of the root system. Specifically, it is the subgroup which is generated by reflections through the hyperplanes… …
80Fuchsian group — In mathematics, a Fuchsian group is a particular type of group of isometries of the hyperbolic plane. A Fuchsian group is always a discrete group contained in the semisimple Lie group PSL(2,C). The name is given in honour of Immanuel Lazarus… …
