On the minimal reducible bound for outerplanar and planar graphs
✍ Scribed by Peter Mihók
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 223 KB
- Volume
- 150
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
✦ Synopsis
Let L be the set of all additive and hereditary properties of graphs. For P1, P2 E L we define the reducible property R = P1P2 as follows: G E PtP2 if there is a bipartition (V~,/1"2) of V(G) such that (V~) E Pi and (V2) E P2. For a property P E L, a reducible property R is called a minimal reducible bound for P if P C_ R and for each reducible property R ', R ' C R ~ P ~ R'. It is proved that the class of all outerplanar graphs has exactly two minimal reducible bounds in L. Some related problems for planar graphs are discussed.
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## Abstract Every 3‐connected planar, cubic, triangle‐free graph with __n__ vertices has a bipartite subgraph with at least 29__n__/24 − 7/6 edges. The constant 29/24 improves the previously best known constant 6/5 which was considered best possible because of the graph of the dodecahedron. Example