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Finite Type (other)
Finite type refers to several related concepts in mathematics: * Algebra of finite type, an associative algebra with finitely many generator **Morphism of finite type, a morphism of schemes with underlying morphisms on affine opens given by algebras of finite type **Scheme of finite type, a scheme over a field with a structure morphism of finite type * Coxeter group of finite type, a Coxeter group whose Schläfli matrix has only positive eigenvalues ** Coxeter matrix of finite type, a Coxeter matrix whose associated Schläfli matrix has only positive eigenvalues **Artin group of finite type, an Artin group arising as the finite Coxeter group of a Coxeter matrix of finite type *Finite type invariant, a knot invariant that vanishes on knots with finitely many singularities *Subshift of finite type In mathematics, subshifts of finite type are used to model dynamical systems, and in particular are the objects of study in symbolic dynamics and ergodic theory. They also describe the set of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algebra Of Finite Type
In mathematics, a finitely generated algebra (also called an algebra of finite type) is a commutative associative algebra ''A'' over a field ''K'' where there exists a finite set of elements ''a''1,...,''a''''n'' of ''A'' such that every element of ''A'' can be expressed as a polynomial in ''a''1,...,''a''''n'', with coefficients in ''K''. Equivalently, there exist elements a_1,\dots,a_n\in A s.t. the evaluation homomorphism at =(a_1,\dots,a_n) :\phi_\colon K _1,\dots,X_ntwoheadrightarrow A is surjective; thus, by applying the first isomorphism theorem, A \simeq K _1,\dots,X_n(\phi_). Conversely, A:= K _1,\dots,X_nI for any ideal I\subset K _1,\dots,X_n/math> is a K-algebra of finite type, indeed any element of A is a polynomial in the cosets a_i:=X_i+I, i=1,\dots,n with coefficients in K. Therefore, we obtain the following characterisation of finitely generated K-algebras :A is a finitely generated K-algebra if and only if it is isomorphic to a quotient ring of the type K _ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphism Of Finite Type
For a homomorphism ''A'' → ''B'' of commutative rings, ''B'' is called an ''A''-algebra of finite type if ''B'' is a finitely generated as an ''A''-algebra. It is much stronger for ''B'' to be a finite ''A''-algebra, which means that ''B'' is finitely generated as an ''A''-module. For example, for any commutative ring ''A'' and natural number ''n'', the polynomial ring ''A'' 'x''1, ..., ''xn''is an ''A''-algebra of finite type, but it is not a finite ''A''-module unless ''A'' = 0 or ''n'' = 0. Another example of a finite-type morphism which is not finite is \mathbb \to \mathbb x,y]/(y^2 - x^3 - t). The analogous notion in terms of schemes is: a morphism ''f'': ''X'' → ''Y'' of schemes is of finite type if ''Y'' has a covering by affine open subschemes ''Vi'' = Spec ''Ai'' such that ''f''−1(''Vi'') has a finite covering by affine open subschemes ''Uij'' = Spec ''Bij'' with ''Bij'' an ''Ai''-algebra of finite type. One also says that ''X'' is of finite type over ''Y''. For exa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scheme Of Finite Type
For a homomorphism ''A'' → ''B'' of commutative rings, ''B'' is called an ''A''-algebra of finite type if ''B'' is a finitely generated as an ''A''-algebra. It is much stronger for ''B'' to be a finite ''A''-algebra, which means that ''B'' is finitely generated as an ''A''-module. For example, for any commutative ring ''A'' and natural number ''n'', the polynomial ring ''A'' 'x''1, ..., ''xn''is an ''A''-algebra of finite type, but it is not a finite ''A''-module unless ''A'' = 0 or ''n'' = 0. Another example of a finite-type morphism which is not finite is \mathbb \to \mathbb x,y]/(y^2 - x^3 - t). The analogous notion in terms of schemes is: a morphism ''f'': ''X'' → ''Y'' of schemes is of finite type if ''Y'' has a covering by affine open subschemes ''Vi'' = Spec ''Ai'' such that ''f''−1(''Vi'') has a finite covering by affine open subschemes ''Uij'' = Spec ''Bij'' with ''Bij'' an ''Ai''-algebra of finite type. One also says that ''X'' is of finite type over ''Y''. For exa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coxeter Group Of Finite Type
In mathematics, a Coxeter group, named after H. S. M. Coxeter, is an abstract group that admits a formal description in terms of reflections (or kaleidoscopic mirrors). Indeed, the finite Coxeter groups are precisely the finite Euclidean reflection groups; the symmetry groups of regular polyhedra are an example. However, not all Coxeter groups are finite, and not all can be described in terms of symmetries and Euclidean reflections. Coxeter groups were introduced in 1934 as abstractions of reflection groups , and finite Coxeter groups were classified in 1935 . Coxeter groups find applications in many areas of mathematics. Examples of finite Coxeter groups include the symmetry groups of regular polytopes, and the Weyl groups of simple Lie algebras. Examples of infinite Coxeter groups include the triangle groups corresponding to regular tessellations of the Euclidean plane and the hyperbolic plane, and the Weyl groups of infinite-dimensional Kac–Moody algebras. Standa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coxeter Matrix Of Finite Type
In mathematics, a Coxeter group, named after H. S. M. Coxeter, is an abstract group that admits a formal description in terms of reflections (or kaleidoscopic mirrors). Indeed, the finite Coxeter groups are precisely the finite Euclidean reflection groups; the symmetry groups of regular polyhedra are an example. However, not all Coxeter groups are finite, and not all can be described in terms of symmetries and Euclidean reflections. Coxeter groups were introduced in 1934 as abstractions of reflection groups , and finite Coxeter groups were classified in 1935 . Coxeter groups find applications in many areas of mathematics. Examples of finite Coxeter groups include the symmetry groups of regular polytopes, and the Weyl groups of simple Lie algebras. Examples of infinite Coxeter groups include the triangle groups corresponding to regular tessellations of the Euclidean plane and the hyperbolic plane, and the Weyl groups of infinite-dimensional Kac–Moody algebras. Standa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artin Group Of Finite Type
Artin may refer to: * Artin (name), a surname and given name, including a list of people with the name ** Artin, a variant of Harutyun Harutyun ( hy, Հարություն and in Western Armenian Յարութիւն) also spelled Haroutioun, Harutiun and its variants Harout, Harut and Artin is a common male Armenian name; it means resurrection in Armenian. People with the name H ..., an Armenian given name * 15378 Artin, a main-belt asteroid See also {{disambiguation, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finite Type Invariant
In the mathematical theory of knots, a finite type invariant, or Vassiliev invariant (so named after Victor Anatolyevich Vassiliev), is a knot invariant that can be extended (in a precise manner to be described) to an invariant of certain singular knots that vanishes on singular knots with ''m'' + 1 singularities and does not vanish on some singular knot with 'm' singularities. It is then said to be of type or order m. We give the combinatorial definition of finite type invariant due to Goussarov, and (independently) Joan Birman and Xiao-Song Lin. Let ''V'' be a knot invariant. Define ''V''1 to be defined on a knot with one transverse singularity. Consider a knot ''K'' to be a smooth embedding of a circle into \R^3. Let ''K be a smooth immersion of a circle into \mathbb R^3 with one transverse double point. Then : V^1(K') = V(K_+) - V(K_-), where K_+ is obtained from ''K'' by resolving the double point by pushing up one strand above the other, and ''K_-'' is obta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
