• 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...
    64 KB (10,258 words) - 11:00, 30 April 2025
  • colimits, like the strongly related notions of universal properties and adjoint functors, exist at a high level of abstraction. In order to understand them...
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    concept of adjoint functors was introduced independently by Daniel Kan in 1958. Mathematics portal Free object Natural transformation Adjoint functor Monad...
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  • Topos (redirect from Logical functors)
    : X → Y {\displaystyle u:X\to Y} is a pair of adjoint functors (u∗,u∗) (where u∗ : Y → X is left adjoint to u∗ : X → Y) such that u∗ preserves finite limits...
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    Adjoint functors: A functor can be left (or right) adjoint to another functor that maps in the opposite direction. Such a pair of adjoint functors typically...
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  • mathematics, the formal criteria for adjoint functors are criteria for the existence of a left or right adjoint of a given functor. One criterion is the following...
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  • in topology and more generally model categories. Two functors F: C → D and G: D → C are adjoint if for all objects c in C and d in D HomD(F(c), d) ≅ HomC(c...
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  • transpose or algebraic adjoint of a linear map is often used to study the original linear map. This concept is generalised by adjoint functors. Let X # {\displaystyle...
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  • Natural transformation (category Functors)
    to be a "morphism of functors". Informally, the notion of a natural transformation states that a particular map between functors can be done consistently...
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  • pairs of adjoint functors. Functors sometimes appear in functional programming. For instance, the programming language Haskell has a class Functor where...
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  • are functors adjoint to each other, then T = G ∘ F {\displaystyle T=G\circ F} together with η , μ {\displaystyle \eta ,\mu } determined by the adjoint relation...
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  • (f\colon X\to Z)\mapsto (f^{Y}\colon X^{Y}\to Z^{Y})} , is a right adjoint to the product functor − × Y {\displaystyle -\times Y} . For this reason, the morphisms...
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    Cat is naturally a 2-category, with functors as its arrows and natural transformations as the arrows between functors. In this setting, commutative diagrams...
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  • properties and adjoint functors. Let 1 be the discrete category with a single object (denoted by •), and let U : C → 1 be the unique (constant) functor to 1. Then...
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  • Look up adjoint in Wiktionary, the free dictionary. In mathematics, the term adjoint applies in several situations. Several of these share a similar formalism:...
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  • F:{\text{Hom}}(A,B)\rightarrow {\text{Hom}}(F(A),F(B))} is a group homomorphism. Most functors studied between preadditive categories are additive. For a simple example...
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  • to the defining properties of pairs of adjoint functors in category theory, and this is where adjoint functors got their name. Mathematical concepts Conjugate...
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  • of a forgetful functor with no adjoint. There is no field satisfying a free universal property for a given set. Adjoint functors Functors Projection (set...
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  • requirement that the functor – ×Y (i.e. the functor from C to C that maps objects X to X ×Y and morphisms φ to φ × idY) has a right adjoint, usually denoted...
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  • then just a contravariant functor I → C. Let C I o p {\displaystyle C^{I^{\mathrm {op} }}} be the category of these functors (with natural transformations...
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  • Thumbnail for William Lawvere
    and universal quantifiers can be characterized as special cases of adjoint functors. Back in Zürich for 1968 and 1969 he proposed elementary (first-order)...
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  • must be additive functors (see here). Most of the interesting functors studied in category theory are adjoints. When considering functors between R-linear...
    15 KB (1,571 words) - 17:59, 14 December 2024
  • pre-abelian category, exact functors can be described in particularly simple terms. First, recall that an additive functor is a functor F: C → D between preadditive...
    10 KB (1,382 words) - 03:45, 26 March 2024
  • forgetful functors A : Ring → Ab M : Ring → Mon which "forget" multiplication and addition, respectively. Both of these functors have left adjoints. The left...
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  • relative to ≤. The term "adjoint" refers to the fact that monotone Galois connections are special cases of pairs of adjoint functors in category theory as...
    34 KB (4,177 words) - 21:23, 15 March 2025
  • a branch of mathematics, a functor category D C {\displaystyle D^{C}} is a category where the objects are the functors F : C → D {\displaystyle F:C\to...
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  • adjoint functors ( j ! , j ∗ , j ∗ ) {\displaystyle (j_{!},j^{*},j_{*})} and ( i ∗ , i ∗ , i ! ) {\displaystyle (i^{*},i_{*},i^{!})} . The functors i...
    32 KB (6,305 words) - 19:57, 18 January 2025
  • this context, the duality is often called Eckmann–Hilton duality. Adjoint functor Dual object Duality (mathematics) Opposite category Pulation square...
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  • Isomorphism of categories (category Adjoint functors)
    functor category C1, with objects functors c: 1 → C, selecting an object c∈Ob(C), and arrows natural transformations f: c → d between these functors,...
    5 KB (755 words) - 15:45, 11 April 2025
  • as the existence of a right adjoint functor f ! {\displaystyle f^{!}} , called twisted or exceptional inverse image functor, to a higher direct image with...
    12 KB (1,897 words) - 23:12, 1 October 2024