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Nichols Algebra
In algebra, the Nichols algebra of a braided vector space (with the braiding often induced by a finite group) is a braided Hopf algebra which is denoted by \mathfrak(V) and named after the mathematician Warren Nichols. It takes the role of quantum Borel part of a pointed Hopf algebra such as a quantum groups and their well known finite-dimensional truncations. Nichols algebras can immediately be used to write down new such quantum groups by using the Radford biproduct. The classification of all such Nichols algebras and even all associated quantum groups (see Application) has been progressing rapidly, although still much is open: The case of an abelian group was solved in 2005, but otherwise this phenomenon seems to be very rare, with a handful examples known and powerful negation criteria established (see below). See also this List of finite-dimensional Nichols algebras. The finite-dimensional theory is greatly governed by a theory of root systems and Dynkin diagrams, strikingl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braided Vector Space
In mathematics, a braided vectorspace \;V is a vector space together with an additional structure map \tau symbolizing interchanging of two vector tensor copies: ::\tau:\; V\otimes V\longrightarrow V\otimes V such that the Yang–Baxter equation is fulfilled. Hence drawing tensor diagrams with \tau an overcrossing the corresponding composed morphism is unchanged when a Reidemeister move is applied to the tensor diagram and thus they present a representation of the braid group. As first example, every vector space is braided via the trivial braiding (simply flipping). A superspace has a braiding with negative sign in braiding two odd vectors. More generally, a diagonal braiding means that for a \;V-base x_i we have ::\tau(x_i\otimes x_j)=q_(x_j\otimes x_i) A good source for braided vector spaces entire braided monoidal categories with braidings between any objects \tau_, most importantly the modules over quasitriangular Hopf algebras and Yetter–Drinfeld modules over finit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supersymmetry As A Quantum Group
In a supersymmetric theory the equations for force and the equations for matter are identical. In theoretical and mathematical physics, any theory with this property has the principle of supersymmetry (SUSY). Dozens of supersymmetric theories exist. Supersymmetry is a spacetime symmetry between two basic classes of particles: bosons, which have an integer-valued spin and follow Bose–Einstein statistics, and fermions, which have a half-integer-valued spin and follow Fermi–Dirac statistics. In supersymmetry, each particle from one class would have an associated particle in the other, known as its superpartner, the spin of which differs by a half-integer. For example, if the electron exists in a supersymmetric theory, then there would be a particle called a ''"selectron"'' (superpartner electron), a bosonic partner of the electron. In the simplest supersymmetry theories, with perfectly " unbroken" supersymmetry, each pair of superpartners would share the same mass and internal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuboctahedron
A cuboctahedron is a polyhedron with 8 triangular faces and 6 square faces. A cuboctahedron has 12 identical vertices, with 2 triangles and 2 squares meeting at each, and 24 identical edges, each separating a triangle from a square. As such, it is a quasiregular polyhedron, i.e. an Archimedean solid that is not only vertex-transitive but also edge-transitive. It is radially equilateral. Its dual polyhedron is the rhombic dodecahedron. The cuboctahedron was probably known to Plato: Heron's ''Definitiones'' quotes Archimedes as saying that Plato knew of a solid made of 8 triangles and 6 squares. Synonyms *''Vector Equilibrium'' (Buckminster Fuller) because its center-to-vertex radius equals its edge length (it has radial equilateral symmetry). Fuller also called a cuboctahedron built of rigid struts and flexible vertices a ''jitterbug''; this object can be progressively transformed into an icosahedron, octahedron, and tetrahedron by folding along the diagonals of its square sid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Sum
The direct sum is an operation between structures in abstract algebra, a branch of mathematics. It is defined differently, but analogously, for different kinds of structures. To see how the direct sum is used in abstract algebra, consider a more elementary kind of structure, the abelian group. The direct sum of two abelian groups A and B is another abelian group A\oplus B consisting of the ordered pairs (a,b) where a \in A and b \in B. To add ordered pairs, we define the sum (a, b) + (c, d) to be (a + c, b + d); in other words addition is defined coordinate-wise. For example, the direct sum \Reals \oplus \Reals , where \Reals is real coordinate space, is the Cartesian plane, \R ^2 . A similar process can be used to form the direct sum of two vector spaces or two modules. We can also form direct sums with any finite number of summands, for example A \oplus B \oplus C, provided A, B, and C are the same kinds of algebraic structures (e.g., all abelian groups, or all vector spa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centralizer And Normalizer
In mathematics, especially group theory, the centralizer (also called commutant) of a subset ''S'' in a group ''G'' is the set of elements \mathrm_G(S) of ''G'' such that each member g \in \mathrm_G(S) commutes with each element of ''S'', or equivalently, such that conjugation by g leaves each element of ''S'' fixed. The normalizer of ''S'' in ''G'' is the set of elements \mathrm_G(S) of ''G'' that satisfy the weaker condition of leaving the set S \subseteq G fixed under conjugation. The centralizer and normalizer of ''S'' are subgroups of ''G''. Many techniques in group theory are based on studying the centralizers and normalizers of suitable subsets ''S''. Suitably formulated, the definitions also apply to semigroups. In ring theory, the centralizer of a subset of a ring is defined with respect to the semigroup (multiplication) operation of the ring. The centralizer of a subset of a ring ''R'' is a subring of ''R''. This article also deals with centralizers and normaliz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjugacy Class
In mathematics, especially group theory, two elements a and b of a group are conjugate if there is an element g in the group such that b = gag^. This is an equivalence relation whose equivalence classes are called conjugacy classes. In other words, each conjugacy class is closed under b = gag^. for all elements g in the group. Members of the same conjugacy class cannot be distinguished by using only the group structure, and therefore share many properties. The study of conjugacy classes of non-abelian groups is fundamental for the study of their structure. For an abelian group, each conjugacy class is a set containing one element (singleton set). Functions that are constant for members of the same conjugacy class are called class functions. Definition Let G be a group. Two elements a, b \in G are conjugate if there exists an element g \in G such that gag^ = b, in which case b is called of a and a is called a conjugate of b. In the case of the general linear group \operatorna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynkin Diagram G2b
Dynkin (Russian: Дынкин) is a Russian masculine surname, its feminine counterpart is Dynkina. It may refer to the following notable people: * Aleksandr Dynkin, Russian economist * Eugene Dynkin (1924–2014), Soviet and American mathematician known for ** Dynkin diagram ** Coxeter–Dynkin diagram ** Dynkin system ** Dynkin's formula ** Doob–Dynkin lemma ** Dynkin index In mathematics, the Dynkin index I() of a finite-dimensional highest-weight representation of a compact simple Lie algebra \mathfrak g with highest weight \lambda is defined by \text_= 2I(\lambda) \text_, where V_0 is the 'defining representat ... {{surname Russian-language surnames ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynkin Diagram B2
Dynkin (Russian: Дынкин) is a Russian masculine surname, its feminine counterpart is Dynkina. It may refer to the following notable people: * Aleksandr Dynkin, Russian economist * Eugene Dynkin (1924–2014), Soviet and American mathematician known for ** Dynkin diagram ** Coxeter–Dynkin diagram ** Dynkin system ** Dynkin's formula ** Doob–Dynkin lemma ** Dynkin index In mathematics, the Dynkin index I() of a finite-dimensional highest-weight representation of a compact simple Lie algebra \mathfrak g with highest weight \lambda is defined by \text_= 2I(\lambda) \text_, where V_0 is the 'defining representat ... {{surname Russian-language surnames ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynkin Diagram A2
Dynkin (Russian: Дынкин) is a Russian masculine surname, its feminine counterpart is Dynkina. It may refer to the following notable people: * Aleksandr Dynkin, Russian economist * Eugene Dynkin (1924–2014), Soviet and American mathematician known for ** Dynkin diagram ** Coxeter–Dynkin diagram ** Dynkin system ** Dynkin's formula ** Doob–Dynkin lemma ** Dynkin index In mathematics, the Dynkin index I() of a finite-dimensional highest-weight representation of a compact simple Lie algebra \mathfrak g with highest weight \lambda is defined by \text_= 2I(\lambda) \text_, where V_0 is the 'defining representat ... {{surname Russian-language surnames ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynkin Diagram A1A1
Dynkin (Russian: Дынкин) is a Russian masculine surname, its feminine counterpart is Dynkina. It may refer to the following notable people: * Aleksandr Dynkin, Russian economist * Eugene Dynkin (1924–2014), Soviet and American mathematician known for ** Dynkin diagram ** Coxeter–Dynkin diagram ** Dynkin system ** Dynkin's formula ** Doob–Dynkin lemma ** Dynkin index In mathematics, the Dynkin index I() of a finite-dimensional highest-weight representation of a compact simple Lie algebra \mathfrak g with highest weight \lambda is defined by \text_= 2I(\lambda) \text_, where V_0 is the 'defining representat ... {{surname Russian-language surnames ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root System
In mathematics, a root system is a configuration of vectors in a Euclidean space satisfying certain geometrical properties. The concept is fundamental in the theory of Lie groups and Lie algebras, especially the classification and representation theory of semisimple Lie algebras. Since Lie groups (and some analogues such as algebraic groups) and Lie algebras have become important in many parts of mathematics during the twentieth century, the apparently special nature of root systems belies the number of areas in which they are applied. Further, the classification scheme for root systems, by Dynkin diagrams, occurs in parts of mathematics with no overt connection to Lie theory (such as singularity theory). Finally, root systems are important for their own sake, as in spectral graph theory. Definitions and examples As a first example, consider the six vectors in 2-dimensional Euclidean space, R2, as shown in the image at the right; call them roots. These vectors Linear span, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
