Abstract
Let mad (G) denote the maximum average degree (over all subgraphs) of G and let χ i (G) denote the injective chromatic number of G. We prove that if Δ≥4 and \(\mathrm{mad}(G)<\frac{14}{5}\), then χ i (G)≤Δ+2. When Δ=3, we show that \(\mathrm{mad}(G)<\frac{36}{13}\) implies χ i (G)≤5. In contrast, we give a graph G with Δ=3, \(\mathrm{mad}(G)=\frac{36}{13}\), and χ i (G)=6.
Similar content being viewed by others
References
Borodin, O.V.: On the total coloring of planar graphs. J. Reine Angew. Math. 394, 180–185 (1989)
Borodin, O.V.: An extension of Kotzig’s theorem and the list edge colouring of planar graphs. Mat. Zametki 48, 22–28 (1990) (in Russian)
Borodin, O.V., Kostochka, A.V., Woodall, D.R.: List edge and list total colourings of multigraphs. J. Comb. Theory B 71, 184–204 (1997)
Chudnovsky, M., Robertson, N., Seymour, P., Thomas, R.: The strong perfect graph theorem. Ann. Math. 164(1), 51–229 (2006). http://annals.princeton.edu/annals/2006/164-1/p02.xhtml
Cornuéjols, G.: The strong perfect graph theorem. Optima 70, 2–6 (2003). http://integer.tepper.cmu.edu/webpub/optima.pdf
Cranston, D.W., Kim, S.-J.: List-coloring the square of a subcubic graph. J. Graph Theory 57, 65–87 (2008)
Cranston, D.W., Kim, S.-J., Yu, G.: Injective colorings of sparse graphs. Discrete Math. (to appear)
Doyon, A., Hahn, G., Raspaud, A.: On the injective chromatic number of sparse graphs. Discrete Math. 310(3), 585–590 (2010)
Erdős, P., Rubin, A., Taylor, H.: Choosability in graphs. Congr. Numer. 26, 125–157 (1979)
Fridrich, J., Lisonek, P.: Grid colorings in steganography. IEEE Trans. Inf. Theory 53, 1547–1549 (2007)
Garey, M.R., Johnson, D.S.: Computers and Intractability: A Guide to the Theory of NP-completeness. Freeman, New York (1979)
Hahn, G., Kratochvíl, J., Širáň, J., Sotteau, D.: On the injective chromatic number of graphs. Discrete Math. 256, 179–192 (2002)
Hahn, G., Raspaud, A., Wang, W.: On the injective coloring of K 4-minor free graphs. Preprint (2006). http://www.labri.fr/perso/lepine/Rapports_internes/RR-140106.ps.gz
van den Heuvel, J., McGuinness, S.: Coloring the square of a planar graph. J. Graph Theory 42, 110–124 (2002)
Lužar, B., Škrekovski, R., Tancer, M.: Injective colorings of planar graphs with few colors. Discrete Math. 309(18), 5636–5649 (2009)
Molloy, M., Salavatipour, M.R.: A bound on the chromatic number of the square of a planar graph. J. Comb. Theory B 94, 189–213 (2005)
Robertson, N., Sanders, D.P., Seymour, P.D., Thomas, R.: The four colour theorem. J. Comb. Theory B 70, 2–44 (1997)
Robertson, N., Sanders, D.P., Seymour, P.D., Thomas, R.: The four color theorem. http://people.math.gatech.edu/~thomas/FC/fourcolor.html
Seymour, P.: How the proof of the strong perfect graph conjecture was found. http://users.encs.concordia.ca/~chvatal/perfect/pds.pdf
Vizing, V.G.: Coloring the vertices of a graph in prescribed colors. Diskretn. Anal. 29, 3–10 (1976) (in Russian)
Author information
Authors and Affiliations
Corresponding author
Additional information
Research of S.-J. Kim supported by the Korea Research Foundation Grant funded by the Korean Government (KRF-2008-313-C00115).
Research of G. Yu supported in part by the NSF grant DMS-0852452.
Rights and permissions
About this article
Cite this article
Cranston, D.W., Kim, SJ. & Yu, G. Injective Colorings of Graphs with Low Average Degree. Algorithmica 60, 553–568 (2011). https://doi.org/10.1007/s00453-010-9425-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00453-010-9425-x