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On the parity of planar covers

✍ Scribed by Dan Archdeacon; R. Bruce Richter

Publisher
John Wiley and Sons
Year
1990
Tongue
English
Weight
263 KB
Volume
14
Category
Article
ISSN
0364-9024

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✦ Synopsis

Abstract

A covering is a graph map Ο•: G β†’ H that is an isomorphism when restricted to the star of any vertex of G. If H is connected then |Ο•^βˆ’1^(v)| is constant. This constant is called the fold number. In this paper we prove that if G is a planar graph that covers a nonplanar H, then the fold number must be even.

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