Decomposing a planar graph of girth 5 into an independent set and a forest
Publication: Research - peer-review › Journal article – Annual report year: 2009
We use a list-color technique to extend the result of Borodin and Glebov that the vertex set of every planar graph of girth at least 5 can be partitioned into an independent set and a set which induces a forest. We apply this extension to also extend Grötzsch's theorem that every planar triangle-free graph is 3-colorable. Let G be a plane graph. Assume that the distance between any two triangles is at least 4. Assume also that each triangle contains a vertex such that this vertex is on the outer face boundary and is not contained in any 4-cycle. Then G has chromatic number at most 3. Note that, in this extension of Grötzsch's theorem an unbounded number of triangles are allowed.
| Original language | English |
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| Journal | Journal of Combinatorial Theory. Series B |
| Publication date | 2009 |
| Volume | 99 |
| Journal number | 4 |
| Pages | 674-684 |
| ISSN | 0095-8956 |
| DOIs | |
| State | Published |
| Citations | Web of Science® Times Cited: 1 |
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Keywords
- Forests, Independent sets, Planar graphs of girth 5
ID: 3420045