Chromatic Sums for Colorings Avoiding Monochromatic Subgraphs
Discussiones Mathematicae. Graph Theory, Tome 35 (2015) no. 3, pp. 541-555
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Given graphs G and H, a vertex coloring c : V (G) →ℕ is an H-free coloring of G if no color class contains a subgraph isomorphic to H. The H-free chromatic number of G, χ (H,G), is the minimum number of colors in an H-free coloring of G. The H-free chromatic sum of G, ∑(H,G), is the minimum value achieved by summing the vertex colors of each H-free coloring of G. We provide a general bound for ∑(H,G), discuss the computational complexity of finding this parameter for different choices of H, and prove an exact formulas for some graphs G. For every integer k and for every graph H, we construct families of graphs, Gk with the property that k more colors than χ (H,G) are required to realize ∑(H,G) for H-free colorings. More complexity results and constructions of graphs requiring extra colors are given for planar and outerplanar graphs.
Keywords:
coloring, sum of colors, forbidden subgraphs
@article{DMGT_2015_35_3_a11,
author = {Kubicka, Ewa and Kubicki, Grzegorz and McKeon, Kathleen A.},
title = {Chromatic {Sums} for {Colorings} {Avoiding} {Monochromatic} {Subgraphs}},
journal = {Discussiones Mathematicae. Graph Theory},
pages = {541--555},
publisher = {mathdoc},
volume = {35},
number = {3},
year = {2015},
language = {en},
url = {http://geodesic.mathdoc.fr/item/DMGT_2015_35_3_a11/}
}
TY - JOUR AU - Kubicka, Ewa AU - Kubicki, Grzegorz AU - McKeon, Kathleen A. TI - Chromatic Sums for Colorings Avoiding Monochromatic Subgraphs JO - Discussiones Mathematicae. Graph Theory PY - 2015 SP - 541 EP - 555 VL - 35 IS - 3 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/DMGT_2015_35_3_a11/ LA - en ID - DMGT_2015_35_3_a11 ER -
%0 Journal Article %A Kubicka, Ewa %A Kubicki, Grzegorz %A McKeon, Kathleen A. %T Chromatic Sums for Colorings Avoiding Monochromatic Subgraphs %J Discussiones Mathematicae. Graph Theory %D 2015 %P 541-555 %V 35 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/DMGT_2015_35_3_a11/ %G en %F DMGT_2015_35_3_a11
Kubicka, Ewa; Kubicki, Grzegorz; McKeon, Kathleen A. Chromatic Sums for Colorings Avoiding Monochromatic Subgraphs. Discussiones Mathematicae. Graph Theory, Tome 35 (2015) no. 3, pp. 541-555. http://geodesic.mathdoc.fr/item/DMGT_2015_35_3_a11/