Displaying similar documents to “The relation between homotopy limits and Bauer's shape singular complex”

Polyhedra with finite fundamental group dominate finitely many different homotopy types

Danuta Kołodziejczyk (2003)

Fundamenta Mathematicae

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In 1968 K. Borsuk asked: Does every polyhedron dominate only finitely many different shapes? In this question the notion of shape can be replaced by the notion of homotopy type. We showed earlier that the answer to the Borsuk question is no. However, in a previous paper we proved that every simply connected polyhedron dominates only finitely many different homotopy types (equivalently, shapes). Here we prove that the same is true for polyhedra with finite fundamental group.

Homotopy dominations within polyhedra

Danuta Kołodziejczyk (2003)

Fundamenta Mathematicae

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We show the existence of a finite polyhedron P dominating infinitely many different homotopy types of finite polyhedra and such that there is a bound on the lengths of all strictly descending sequences of homotopy types dominated by P. This answers a question of K. Borsuk (1979) dealing with shape-theoretic notions of "capacity" and "depth" of compact metric spaces. Moreover, π₁(P) may be any given non-abelian poly-ℤ-group and dim P may be any given integer n ≥ 3.