A remark on the (2,2)-domination number

Torsten Korneffel; Dirk Meierling; Lutz Volkmann

Discussiones Mathematicae Graph Theory (2008)

  • Volume: 28, Issue: 2, page 361-366
  • ISSN: 2083-5892

Abstract

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A subset D of the vertex set of a graph G is a (k,p)-dominating set if every vertex v ∈ V(G)∖D is within distance k to at least p vertices in D. The parameter γ k , p ( G ) denotes the minimum cardinality of a (k,p)-dominating set of G. In 1994, Bean, Henning and Swart posed the conjecture that γ k , p ( G ) ( p / ( p + k ) ) n ( G ) for any graph G with δₖ(G) ≥ k+p-1, where the latter means that every vertex is within distance k to at least k+p-1 vertices other than itself. In 2005, Fischermann and Volkmann confirmed this conjecture for all integers k and p for the case that p is a multiple of k. In this paper we show that γ 2 , 2 ( G ) ( n ( G ) + 1 ) / 2 for all connected graphs G and characterize all connected graphs with γ 2 , 2 = ( n + 1 ) / 2 . This means that for k = p = 2 we characterize all connected graphs for which the conjecture is true without the precondition that δ₂ ≥ 3.

How to cite

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Torsten Korneffel, Dirk Meierling, and Lutz Volkmann. "A remark on the (2,2)-domination number." Discussiones Mathematicae Graph Theory 28.2 (2008): 361-366. <http://eudml.org/doc/270462>.

@article{TorstenKorneffel2008,
abstract = {A subset D of the vertex set of a graph G is a (k,p)-dominating set if every vertex v ∈ V(G)∖D is within distance k to at least p vertices in D. The parameter $γ_\{k,p\}(G)$ denotes the minimum cardinality of a (k,p)-dominating set of G. In 1994, Bean, Henning and Swart posed the conjecture that $γ_\{k,p\}(G) ≤ (p/(p+k))n(G)$ for any graph G with δₖ(G) ≥ k+p-1, where the latter means that every vertex is within distance k to at least k+p-1 vertices other than itself. In 2005, Fischermann and Volkmann confirmed this conjecture for all integers k and p for the case that p is a multiple of k. In this paper we show that $γ_\{2,2\}(G) ≤ (n(G)+1)/2$ for all connected graphs G and characterize all connected graphs with $γ_\{2,2\} = (n+1)/2$. This means that for k = p = 2 we characterize all connected graphs for which the conjecture is true without the precondition that δ₂ ≥ 3.},
author = {Torsten Korneffel, Dirk Meierling, Lutz Volkmann},
journal = {Discussiones Mathematicae Graph Theory},
keywords = {domination; distance domination number; p-domination number; -domination number},
language = {eng},
number = {2},
pages = {361-366},
title = {A remark on the (2,2)-domination number},
url = {http://eudml.org/doc/270462},
volume = {28},
year = {2008},
}

TY - JOUR
AU - Torsten Korneffel
AU - Dirk Meierling
AU - Lutz Volkmann
TI - A remark on the (2,2)-domination number
JO - Discussiones Mathematicae Graph Theory
PY - 2008
VL - 28
IS - 2
SP - 361
EP - 366
AB - A subset D of the vertex set of a graph G is a (k,p)-dominating set if every vertex v ∈ V(G)∖D is within distance k to at least p vertices in D. The parameter $γ_{k,p}(G)$ denotes the minimum cardinality of a (k,p)-dominating set of G. In 1994, Bean, Henning and Swart posed the conjecture that $γ_{k,p}(G) ≤ (p/(p+k))n(G)$ for any graph G with δₖ(G) ≥ k+p-1, where the latter means that every vertex is within distance k to at least k+p-1 vertices other than itself. In 2005, Fischermann and Volkmann confirmed this conjecture for all integers k and p for the case that p is a multiple of k. In this paper we show that $γ_{2,2}(G) ≤ (n(G)+1)/2$ for all connected graphs G and characterize all connected graphs with $γ_{2,2} = (n+1)/2$. This means that for k = p = 2 we characterize all connected graphs for which the conjecture is true without the precondition that δ₂ ≥ 3.
LA - eng
KW - domination; distance domination number; p-domination number; -domination number
UR - http://eudml.org/doc/270462
ER -

References

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  1. [1] T.J. Bean, M.A. Henning and H.C. Swart, On the integrity of distance domination in graphs, Australas. J. Combin. 10 (1994) 29-43. Zbl0815.05036
  2. [2] E.J. Cockayne, B. Gamble and B. Shepherd, An upper bound for the k-domination number of a graph, J. Graph Theory 9 (1985) 101-102, doi: 10.1002/jgt.3190090414. Zbl0664.05053
  3. [3] M. Fischermann and L. Volkmann, A remark on a conjecture for the (k,p)-domination number, Util. Math. 67 (2005) 223-227. Zbl1077.05074
  4. [4] T.W. Haynes, S.T. Hedetniemi and P.J. Slater, Fundamentals of Domination in Graphs (Marcel Dekker, Inc., New York, 1998). Zbl0890.05002
  5. [5] T.W. Haynes, S.T. Hedetniemi and P.J. Slater, Domination in Graphs, Advanced Topics (Marcel Dekker, Inc., New York, 1998). Zbl0883.00011
  6. [6] A. Meir and J.W. Moon, Relations between packing and covering numbers of a tree, Pacific J. Math. 61 (1975) 225-233. Zbl0315.05102

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