• 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