A 2-outer-independent dominating set of a graph G is a set D of vertices of G such that every vertex of has at least two neighbors in D, and the set is independent. The 2-outer-independent domination number of a graph G, denoted by , is the minimum cardinality of a 2-outer-independent dominating set of G. We prove that for every nontrivial tree T of order n with l leaves we have , and we characterize the trees attaining this upper bound.
Un ensemble 2-dominant extérieurement-indépendant dʼun graphe G est un ensemble D de sommets de G tel que chaque sommet de a au moins deux voisins dans D, et lʼensemble est indépendant. Le nombre de 2-domination extérieurement-indépendante dʼun graphe G, noté par , est le cardinal minimum dʼun ensemble 2-dominant extérieurement-indépendant de G. Nous prouvons lʼinégalité pour tout arbre non trivial T dʼordre n avec l feuilles, et nous caractérisons les arbres atteignant cette borne supérieure.
Accepted:
Published online:
Marcin Krzywkowski 1
@article{CRMATH_2011__349_21-22_1123_0, author = {Marcin Krzywkowski}, title = {An upper bound on the 2-outer-independent domination number of a tree}, journal = {Comptes Rendus. Math\'ematique}, pages = {1123--1125}, publisher = {Elsevier}, volume = {349}, number = {21-22}, year = {2011}, doi = {10.1016/j.crma.2011.10.005}, language = {en}, }
Marcin Krzywkowski. An upper bound on the 2-outer-independent domination number of a tree. Comptes Rendus. Mathématique, Volume 349 (2011) no. 21-22, pp. 1123-1125. doi : 10.1016/j.crma.2011.10.005. https://comptes-rendus.academie-sciences.fr/mathematique/articles/10.1016/j.crma.2011.10.005/
[1] Independence and 2-domination in trees, Australasian Journal of Combinatorics, Volume 33 (2005), pp. 317-327
[2] Locating-domination, 2-domination and independence in trees, Australasian Journal of Combinatorics, Volume 42 (2008), pp. 309-316
[3] n-Domination in graphs, Graph Theory with Applications to Algorithms and Computer Science, Wiley, New York, 1985, pp. 282-300
[4] Independence and 2-domination in bipartite graphs, Australasian Journal of Combinatorics, Volume 40 (2008), pp. 265-268
[5] On graphs with equal domination and 2-domination numbers, Discrete Mathematics, Volume 308 (2008), pp. 2277-2281
[6] Fundamentals of Domination in Graphs, Marcel Dekker, New York, 1998
[7] Domination in Graphs: Advanced Topics (T. Haynes; S. Hedetniemi; P. Slater, eds.), Marcel Dekker, New York, 1998
[8] On graphs with equal 2-domination and connected 2-domination numbers, Mathematica Applicata Yingyong Shuxue, Volume 17 (2004) no. suppl., pp. 88-92
[9] M. Krzywkowski, 2-outer-independent domination in graphs, submitted for publication.
[10] Bounds for the 2-domination number of toroidal grid graphs, International Journal of Computer Mathematics, Volume 86 (2009), pp. 584-588
Cited by Sources:
Comments - Policy