Halin’s Theorem for the Mobius Strip

Dan Archdeacon1, C.Paul Bonnington2, Marisa Debowsky1, Michael Prestidge3
1Dept. of Math. and Stat. University of Vermont Burlington, VT 05405 USA
2Dept. of Mathematics University of Auckland Auckland, New Zealand
3Dept. of Mathematics University of Auckland ‘Auckland, New Zealand

Abstract

Halin’s Theorem characterizes those locally finite infinite graphs that embed in the plane without accumulation points by giving a set of six topologically-excluded subgraphs. We prove the analogous theorem for graphs that embed in an open Möbius strip without accumulation points. There are \(153\) such obstructions under the ray ordering defined herein. There are \(350\) obstructions under the minor ordering. There are \(1225\) obstructions under the topological ordering. The relationship between these graphs and the obstructions to embedding in the projective plane is similar to the relationship between Halin’s graphs and \(\{K_5, K_{3,3}\}.^1\)