Mesocompact space

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

In mathematics, in the field of general topology, a topological space is said to be mesocompact if every open cover has a compact-finite open refinement.[1] That is, given any open cover, we can find an open refinement with the property that every compact set meets only finitely many members of the refinement.[2]

The following facts are true about mesocompactness:

  • Every compact space, and more generally every paracompact space is mesocompact. This follows from the fact that any locally finite cover is automatically compact-finite.
  • Every mesocompact space is metacompact, and hence also orthocompact. This follows from the fact that points are compact, and hence any compact-finite cover is automatically point finite.

Notes[edit]

  1. ^ Hart, Nagata & Vaughan, p200
  2. ^ Pearl, p23

References[edit]

  • K.P. Hart; J. Nagata; J.E. Vaughan, eds. (2004), Encyclopedia of General Topology, Elsevier, ISBN 0-444-50355-2
  • Pearl, Elliott, ed. (2007), Open Problems in Topology II, Elsevier, ISBN 0-444-52208-5