Topological n-cells and Hilbert cubes in inverse limits

[摘要] It has been shown by S. Mardešić that if a compact metrizable space X has dim X ≥ 1 and X is the inverse limit of an inverse sequence of compact triangulated polyhedra with simplicial bonding maps, then X must contain an arc.  We are going  to prove that  if X = (|K a |,p ba ,(A,) )is an inverse system in set theory of triangulated polyhedra|K a |with simplicial  bonding  functions p baand X = lim X,  then  there  exists  a uniquely determined sub-inverse system X X = (|L a |, p ba |L b |,(A, )) of X where for each a, L ais a subcomplex of K a , each p ba |L b |:|L b | → |L a | is  surjective,  and lim X X= X. We shall use this to generalize the Mardešić result by characterizing when the inverse limit of an inverse sequence of triangulated polyhedra with simplicial bonding maps must contain a topological n-cell and do the same in the case of an inverse system of finite triangulated polyhedra with simplicial bonding maps. We shall also characterize when the inverse limit of an inverse sequence of triangulated polyhedra with simplicial bonding maps must contain an embedded copy of the Hilbert cube. In each of the above settings, all the polyhedra have the weak topology or all have the metric topology(these topologies being identical when the polyhedra are finite).

[学科分类] 几何与拓扑

[关键词] Hilbert cube;inverse limit;inverse sequence;inverse system;polyhedron;simplicial inverse system;simplicial map;topological n-cell;triangulation