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Monoidal Adjunction
Suppose that (\mathcal C,\otimes,I) and (\mathcal D,\bullet,J) are two monoidal categories. A monoidal adjunction between two lax monoidal functors :(F,m):(\mathcal C,\otimes,I)\to (\mathcal D,\bullet,J) and (G,n):(\mathcal D,\bullet,J)\to(\mathcal C,\otimes,I) is an adjunction (F,G,\eta,\varepsilon) between the underlying functors, such that the natural transformation In category theory, a branch of mathematics, a natural transformation provides a way of transforming one functor into another while respecting the internal structure (i.e., the composition of morphisms) of the categories involved. Hence, a natur ...s :\eta:1_\Rightarrow G\circ F and \varepsilon:F\circ G\Rightarrow 1_{\mathcal D} are monoidal natural transformations. Lifting adjunctions to monoidal adjunctions Suppose that :(F,m):(\mathcal C,\otimes,I)\to (\mathcal D,\bullet,J) is a lax monoidal functor such that the underlying functor F:\mathcal C\to\mathcal D has a right adjoint G:\mathcal D\to\mathcal C. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoidal Category
In mathematics, a monoidal category (or tensor category) is a category \mathbf C equipped with a bifunctor :\otimes : \mathbf \times \mathbf \to \mathbf that is associative up to a natural isomorphism, and an object ''I'' that is both a left and right identity for ⊗, again up to a natural isomorphism. The associated natural isomorphisms are subject to certain coherence conditions, which ensure that all the relevant diagrams commute. The ordinary tensor product makes vector spaces, abelian groups, ''R''-modules, or ''R''-algebras into monoidal categories. Monoidal categories can be seen as a generalization of these and other examples. Every (small) monoidal category may also be viewed as a "categorification" of an underlying monoid, namely the monoid whose elements are the isomorphism classes of the category's objects and whose binary operation is given by the category's tensor product. A rather different application, of which monoidal categories can be considered an abstractio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lax Monoidal Functor
In category theory, monoidal functors are functors between monoidal categories which preserve the monoidal structure. More specifically, a monoidal functor between two monoidal categories consists of a functor between the categories, along with two ''coherence maps''—a natural transformation and a morphism that preserve monoidal multiplication and unit, respectively. Mathematicians require these coherence maps to satisfy additional properties depending on how strictly they want to preserve the monoidal structure; each of these properties gives rise to a slightly different definition of monoidal functors * The coherence maps of lax monoidal functors satisfy no additional properties; they are not necessarily invertible. * The coherence maps of strong monoidal functors are invertible. * The coherence maps of strict monoidal functors are identity maps. Although we distinguish between these different definitions here, authors may call any one of these simply monoidal functors. Defi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adjoint Functors
In mathematics, specifically category theory, adjunction is a relationship that two functors may exhibit, intuitively corresponding to a weak form of equivalence between two related categories. Two functors that stand in this relationship are known as adjoint functors, one being the left adjoint and the other the right adjoint. Pairs of adjoint functors are ubiquitous in mathematics and often arise from constructions of "optimal solutions" to certain problems (i.e., constructions of objects having a certain universal property), such as the construction of a free group on a set in algebra, or the construction of the Stone–Čech compactification of a topological space in topology. By definition, an adjunction between categories \mathcal and \mathcal is a pair of functors (assumed to be covariant) :F: \mathcal \rightarrow \mathcal and G: \mathcal \rightarrow \mathcal and, for all objects X in \mathcal and Y in \mathcal a bijection between the respective morphism s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Transformation
In category theory, a branch of mathematics, a natural transformation provides a way of transforming one functor into another while respecting the internal structure (i.e., the composition of morphisms) of the categories involved. Hence, a natural transformation can be considered to be a "morphism of functors". Informally, the notion of a natural transformation states that a particular map between functors can be done consistently over an entire category. Indeed, this intuition can be formalized to define so-called functor categories. Natural transformations are, after categories and functors, one of the most fundamental notions of category theory and consequently appear in the majority of its applications. Definition If F and G are functors between the categories C and D , then a natural transformation \eta from F to G is a family of morphisms that satisfies two requirements. # The natural transformation must associate, to every object X in C, a morphism \eta_X : F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoidal Natural Transformation
Suppose that (\mathcal C,\otimes,I) and (\mathcal D,\bullet, J) are two monoidal categories and :(F,m):(\mathcal C,\otimes,I)\to(\mathcal D,\bullet, J) and (G,n):(\mathcal C,\otimes,I)\to(\mathcal D,\bullet, J) are two lax monoidal functors between those categories. A monoidal natural transformation :\theta:(F,m) \to (G,n) between those functors is a natural transformation In category theory, a branch of mathematics, a natural transformation provides a way of transforming one functor into another while respecting the internal structure (i.e., the composition of morphisms) of the categories involved. Hence, a natur ... \theta:F \to G between the underlying functors such that the diagrams : and commute for every objects A and B of \mathcal C (see Definition 11 in ). A symmetric monoidal natural transformation is a monoidal natural transformation between symmetric monoidal functors. References {{DEFAULTSORT:Monoidal Natural Transformation Monoidal categories ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoidal Monad
In category theory, a monoidal monad (T,\eta,\mu,T_,T_0) is a monad (T,\eta,\mu) on a monoidal category (C,\otimes,I) such that the functor T:(C,\otimes,I)\to(C,\otimes,I) is a lax monoidal functor and the natural transformations \eta and \mu are monoidal natural transformations. In other words, T is equipped with coherence maps T_:TA\otimes TB\to T(A\otimes B) and T_0:I\to TI satisfying certain properties (again: they are lax monoidal), and the unit \eta: id \Rightarrow T and multiplication \mu:T^2\Rightarrow T are monoidal natural transformations. By monoidality of \eta, the morphisms T_0 and \eta_I are necessarily equal. All of the above can be compressed into the statement that a monoidal monad is a monad in the 2-category \mathsf of monoidal categories, lax monoidal functors, and monoidal natural transformations. Opmonoidal Monads Opmonoidal monads have been studied under various names. Ieke Moerdijk introduced them as "Hopf monads", while in works of Bruguières and Virel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
