DMGT

ISSN 1234-3099 (print version)

ISSN 2083-5892 (electronic version)

https://doi.org/10.7151/dmgt

Discussiones Mathematicae Graph Theory

Journal Impact Factor (JIF 2023): 0.5

5-year Journal Impact Factor (2023): 0.6

CiteScore (2023): 2.2

SNIP (2023): 0.681

Discussiones Mathematicae Graph Theory

Article in press


Authors:

M.H. Li

Minhui Li

Qinghai Normal University

email: liminhuimath@163.com

S.M. Zhang

Shumin Zhang

Qinghai Normal University

email: zhangshumin@qhnu.edu.cn

C.F. Ye

Chengfu Ye

Qinghai Normal University

email: yechf@qhnu.edu.cn

Title:

The probabilistic upper bounds on the isolation number of a graph

PDF

Source:

Discussiones Mathematicae Graph Theory

Received: 2024-11-18 , Revised: 2025-03-24 , Accepted: 2025-03-24 , Available online: 2025-04-04 , https://doi.org/10.7151/dmgt.2583

Abstract:

Let $G=(V,E)$ be a graph. A subset $S\subseteq V$ is an isolating set of $G$ if the graph induced by the set $V\backslash N[S]$ contains no edge. The size of a smallest isolating set of $G$ is called the isolation number, denoted by $\iota(G)$. \iffalse We say that a vertex $v$ $ve$-dominates each edge incident to a vertex in $N[v]$. A subset $S\subseteq V$ is a vertex-edge dominating set ($ve$-dominating set) of $G$, if there exists a vertex $v\in S$ such that $v$ $ve$-dominates $e$ for each edge $e\in E$. The vertex-edge domination number ($ve$-domination number) $\gamma_{ve}(G)$ is the minimum cardinality of a vertex-edge dominating set of $G$. In fact, for any graph $G$, $\iota(G)$ is equal to $\gamma_{ve}(G)$. \fi In this paper, we obtain the upper bounds on $\iota(G)$ via probabilistic method, and improve the previous bound on $\iota(G)$ given by Caro and Hansberg.

Keywords:

domination, isolating set, isolation number

References:

  1. N. Alon, J.H. Spencer, The Probabilistic Method (John Wiley $\&$ Sons, Inc., Chichester, 2000).
    https://doi.org/10.1002/0471722154
  2. P. Borg, Isolation of connected graphs, Discrete Appl. Math. 339 (2023) 154–165.
    https://doi.org/10.1016/j.dam.2023.05.004
  3. P. Borg, Isolation of cycles, Graphs Combin. 36 (2020) 631–637.
    https://doi.org/10.1007/s00373-020-02143-2
  4. P. Borg and P. Kaemawichanurat, Partial domination of maximal outerplanar graphs, Discrete Appl. Math. 283 (2020) 306–314.
    https://doi.org/10.1016/j.dam.2020.01.005
  5. P. Borg, K. Fenech and P. Kaemawichanurat, Isolation of $k$-cliques II, Discrete Math. 345(7) (2022) 112641.
    https://doi.org/10.1016/j.disc.2021.112641
  6. P. Borg and P. Kaemawichanurat, Extensions of the Art Gallery Theorem, Ann. Comb. 27 (2023) 31–50.
    https://doi.org/10.1007/s00026-022-00620-4
  7. Y. Caro and A. Hansberg, Partial domination–the isolation number of a graph, Filomat 31 (2017) 3925–3944.
    https://doi.org/10.2298/FIL1712925C
  8. J. Chen and S-J. Xu, $P_{5}$-isolation in graphs, Discrete Appl. Math. 340 (2023) 331–349.
    https://doi.org/10.1016/j.dam.2023.07.018
  9. T.W. Haynes, S.T. Hedetniemi and P.J. Slater, Fundamentals of Domination in Graphs (Marcel Dekker, New York, 1998).
    https://doi.org/10.1201/9781482246582
  10. T.W. Haynes, S.T. Hedetniemi and M.A. Henning, Structures of Domination in Graphs, Dev. Math. 66 (Springer, Cham, 2021).
    https://doi.org/10.1007/978-3-030-58892-2
  11. T.W. Haynes, S.T. Hedetniemi and M.A. Henning, Domination in Graphs: Core Concepts, Springer Monogr. Math. (Springer, Cham, 2023).
    https://doi.org/10.1007/978-3-031-09496-5
  12. P. Kaemawichanurat and O. Favaron, Partial domination and irredundance numbers in graphs, Appl. Math. Comput. 457 (2023) 128153.
    https://doi.org/10.1016/j.amc.2023.128153
  13. O. Ore, Theory of Graphs, in: Amer. Math. Soc. Colloq. Publ. 38, (Providence, RI 1962) 206–212.
    https://doi.org/10.1090/coll/038
  14. J.W. Peters, Theoretical and Algorithmic Results on Domination and Connectivity, PhD Thesis (Clemson University, Clemson, 1986).
  15. N.J. Rad, New probabilistic upper bounds on the domination number of a graph, Electron. J. Combin. 26(3) (2019) #P3.28.
    https://doi.org/10.37236/8345
  16. S. Tokunaga, T. Jiarasuksakun and P. Kaemawichanurat, Isolation number of maximal outerplanar graphs, Discrete Appl. Math. 267 (2019) 215-218.
    https://doi.org/10.1016/j.dam.2019.06.011
  17. J. Yan, Isolation of the Diamond Graph, Bull. Malays. Math. Sci. Soc. 45 (2022) 1169–1181.
    https://doi.org/10.1007/s40840-022-01248-6
  18. Y. Yin, X. An and B. Wu, $K_{1,2}$-isolation number of claw-free cubic graphs, Bull. Malays. Math. Sci. Soc. 47 (2024) 75.
    https://doi.org/10.1007/s40840-024-01672-w
  19. G. Zhang and B. Wu, A Note on the cycle isolation number of graphs, Bull. Malays. Math. Sci. Soc. 47 (2024) 57.
    https://doi.org/10.1007/s40840-024-01655-x

Close