Weak homotopy-equivalent topological spaces

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Definition

Two topological spaces X1 and X2are said to be weak homotopy-equivalent or weakly homotopy-equivalent if the following is true:

We can find a collection of topological spaces X1=Y0,Y1,Y2,,Yn=X2 and a collection of continuous maps fi,0in1, such that each fi is a map either from Yi to Yi+1 or a map from Yi+1 to Yi, and further, each fi is a weak homotopy equivalence of topological spaces.

Relation with other equivalence relations

Stronger equivalence relations

Equivalence relation Meaning Proof of implication Proof of strictness (reverse implication failure) Intermediate notions
homeomorphic spaces there is a bijective homeomorphism between the spaces
homotopy-equivalent topological spaces there is a homotopy equivalence of topological spaces between the spaces homotopy-equivalent not implies weak homotopy-equivalent

Weaker equivalence relations

Equivalence relation Meaning Proof of implication Proof of strictness (reverse implication failure) Intermediate notions
Spaces that have isomorphic homotopy groups isomorphic homotopy groups not implies weak homotopy-equivalent
homology-equivalent topological spaces generated by back and forth homology equivalences homology-equivalent not implies weak homotopy-equivalent
Spaces that have isomorphic homology groups isomorphic homology groups not implies weak homotopy-equivalent