## Abstract A cycle in a graph is a set of edges that covers each vertex an even number of times. A cocycle is a collection of edges that intersects each cycle in an even number of edges. A bicycle is a collection of edges that is both a cycle and a cocycle. The cycles, cocycles, and bicycles each
Characterizing planarity using theta graphs
✍ Scribed by Archdeacon, Dan; S?r�n?, Josef
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 87 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
✦ Synopsis
A theta graph is a homeomorph of K 2,3 . In an embedded planar graph the local rotation at one degree-three vertex of a theta graph determines the local rotation at the other degree-three vertex. Using this observation, we give a characterization of planar graphs in terms of balance in an associated signed graph whose vertices are K 1,3 subgraphs and whose edges correspond to theta graphs.
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