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In mathematics, in particular in homotopy theory within algebraic topology, the homotopy lifting property (also known as an instance of the right lifting property or the covering homotopy axiom) is a technical condition on a continuous function from a topological space E to another one, B.
In mathematics, in particular in category theory, the lifting property is a property of a pair of morphisms in a category.It is used in homotopy theory within algebraic topology to define properties of morphisms starting from an explicitly given class of morphisms.
Given two topological spaces X and Y, a homotopy equivalence between X and Y is a pair of continuous maps f : X → Y and g : Y → X, such that g ∘ f is homotopic to the identity map id X and f ∘ g is homotopic to id Y. If such a pair exists, then X and Y are said to be homotopy equivalent, or of the same homotopy type.
This follows from the Homotopy lifting property. The projection of the letter L onto its base interval is a quasifibration, but not a fibration. More generally, the projection M f → I of the mapping cylinder of a map f : X → Y between connected CW complexes onto the unit interval is a quasifibration if and only if π i ( M f , p −1 ( b ...
Because fibrations satisfy the homotopy lifting property, and Δ is contractible; p −1 (Δ) is homotopy equivalent to F. So this partially defined section assigns an element of π n (F) to every (n + 1)-simplex. This is precisely the data of a π n (F)-valued simplicial cochain of degree n + 1 on B, i.e. an element of C n + 1 (B; π n (F)).
The homotopy extension property is depicted in the following diagram If the above diagram (without the dashed map) commutes (this is equivalent to the conditions above), then pair (X,A) has the homotopy extension property if there exists a map f ~ ∙ {\displaystyle {\tilde {f}}_{\bullet }} which makes the diagram commute.
In topology, a fibration is a mapping : that has certain homotopy-theoretic properties in common with fiber bundles. Specifically, under mild technical assumptions a fiber bundle always has the homotopy lifting property or homotopy covering property (see Steenrod (1951, 11.7) for details). This is the defining property of a fibration.
In what follows, let = [,] denote the unit interval.. A map : of topological spaces is called a cofibration [1] pg 51 if for any map : such that there is an extension to (meaning: there is a map ′: such that ′ =), we can extend a homotopy of maps : to a homotopy of maps ′:, where