Displaying similar documents to “On Fox's theory of overlays”

Ultra regular covering space and its automorphism group

Sang-Eon Han (2010)

International Journal of Applied Mathematics and Computer Science

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In order to classify digital spaces in terms of digital-homotopic theoretical tools, a recent paper by Han (2006b) (see also the works of Boxer and Karaca (2008) as well as Han (2007b)) established the notion of regular covering space from the viewpoint of digital covering theory and studied an automorphism group (or Deck's discrete transformation group) of a digital covering. By using these tools, we can calculate digital fundamental groups of some digital spaces and classify digital...

On the existence of universal covering spaces for metric spaces and subsets of the Euclidean plane

G. R. Conner, J. W. Lamoreaux (2005)

Fundamenta Mathematicae

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We prove several results concerning the existence of universal covering spaces for separable metric spaces. To begin, we define several homotopy-theoretic conditions which we then prove are equivalent to the existence of a universal covering space. We use these equivalences to prove that every connected, locally path connected separable metric space whose fundamental group is a free group admits a universal covering space. As an application of these results, we prove the main result...