Abstract
The square coloring of a graph is to color the vertices of a graph at distance at most 2 with different colors. In 1977, Wegner posed a conjecture on square coloring of planar graphs. The conjecture is still open. In this paper, we prove that Wegner’s conjecture is true for planar graphs with girth at least 6.
Similar content being viewed by others
References
Borodin OV, Ivanova AO (2009) 2-distance (Δ+2)-coloring of planar graphs with girth six and Δ≥18. Discrete Math 309:6496–6502
Borodin OV, Ivanova AO (2011) List injective colorings of planar graphs. Discrete Math 311:154–165
Borodin OV, Broersma HJ, Glebov A, van den Heuvel J (2002) Stars and bunches in planar graphs. Part II: General planar graphs and colourings. CDAM Researches Report
Borodin OV, Glebow AN, Ivanova AO, Neustroeva TK, Taskinow VA (2004) Sufficient conditions for planar graphs to be 2-distance (Δ+1)-colorable. Sib Elektron Mat Izv 1:129–141 (in Russian)
Cranston DW, Kim SJ (2008) List-coloring the square of a subcubic graph. J Graph Theory 57:65–78
Dvoŕak Z, Král D, Nejedlý P, Škrekovshi R (2008) Coloring squares of planar graphs with girth six. Eur J Comb 29:838–849
Kim DS, Du D-Z, Pardalos PM (2000) A coloring problem on the n-cube. Discrete Math 103:307–311
Kostochka AV, Woodall DR (2001) Choosablity conjectures and multicircuits. Discrete Math 240:123–143
Molloy M, Salavatipour MR (2005) A bound on the chromatic number of the square of a planar graph. J Comb Theory, Ser B 94:189–213
Thomassen C (2006) The square of a planar cubic graph is 7-colorable. J. Comb. Theory, B (submitted)
van den Heuvel J, McGuinness S (2003) Coloring of the square of planar graph. J Graph Theory 42:110–124
Wan PJ (1997) Near-optimal conflict-free channel set assignments for an optical cluster-based hypercube networks. J Comb Optim 1:179–186
Wang W, Lih KW (2003) Labeling planar graphs with conditions on girth and distance two. SIAM J Discrete Math 17(2):264–275
Wegner G (1977) Graphs with given diameter and a coloring problem. Technical Report. University of Dortmund, Germany
Zhou S (2004) A channel assignment problem for optical networks modelled by Cayley graphs. Theor Comput Sci 310:501–511
Author information
Authors and Affiliations
Corresponding author
Additional information
The project was supported by NSFC (Grant No. 10971198) and Zhejiang Innovation Project (T200905), ZSDZZZZXK08.
Rights and permissions
About this article
Cite this article
Bu, Y., Zhu, X. An optimal square coloring of planar graphs. J Comb Optim 24, 580–592 (2012). https://doi.org/10.1007/s10878-011-9409-z
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10878-011-9409-z