Title of article :
Decomposing a planar graph of girth 5 into an independent set and a forest
Author/Authors :
Kawarabayashi، نويسنده , , Ken-ichi and Thomassen، نويسنده , , Carsten، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2009
Pages :
11
From page :
674
To page :
684
Abstract :
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 Grِtzschʹs 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 Grِtzschʹs theorem an unbounded number of triangles are allowed.
Keywords :
Planar graphs of girth 5 , independent sets , forests
Journal title :
Journal of Combinatorial Theory Series B
Serial Year :
2009
Journal title :
Journal of Combinatorial Theory Series B
Record number :
1528863
Link To Document :
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