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 volume


Authors:

J. Barát

János Barát

Rényi Institute

email: barat@mik.uni-pannon.hu

Z.L. Blázsik

Zoltán L. Blázsik

Rényi Institute, ELKH-ELTE Geometric and Algebraic Combinatorics Research Group, University of Szeged

email: blazsik@renyi.hu

0000-0003-1877-9983

Title:

General sharp upper bounds on the total coalition number

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Source:

Discussiones Mathematicae Graph Theory 44(4) (2024) 1567-1584

Received: 2023-03-08 , Revised: 2023-07-20 , Accepted: 2023-07-20 , Available online: 2023-08-23 , https://doi.org/10.7151/dmgt.2511

Abstract:

Let $G(V,E)$ be a finite, simple, isolate-free graph. Two disjoint sets $A,B\subset V$ form a total coalition in $G$, if none of them is a total dominating set, but their union $A\cup B$ is a total dominating set. A vertex partition $\Psi=\{C_1,C_2,\dots,C_k\}$ is a total coalition partition, if none of the partition classes is a total dominating set, meanwhile for every $i\in\{1,2,\dots,k\}$ there exists a distinct $j\in\{1,2,\dots,k\}$ such that $C_i$ and $C_j$ form a total coalition. The maximum cardinality of a total coalition partition of $G$ is the total coalition number of $G$ and denoted by $TC(G)$. We give a general sharp upper bound on the total coalition number as a function of the maximum degree. We further investigate this optimal case and study the total coalition graph. We show that every graph can be realised as a total coalition graph.

Keywords:

total domination, total coalition partition, total coalition number, total coalition graph

References:

  1. S. Alikhani, D. Bakhshesh and H. Golmohammadi, Total coalitions in graphs (2022).
    arXiv: 2211.11590
  2. E.J. Cockayne, R.M. Dawes and S.T. Hedetniemi, Total domination in graphs, Networks 10 (1980) 211–219.
    https://doi.org/10.1002/net.3230100304
  3. E.J. Cockayne and S.T. Hedetniemi, Towards a theory of domination in graphs, Networks 7 (1977) 247–261.
    https://doi.org/10.1002/net.3230070305
  4. W. Goddard and M.A. Henning, Independent domination in graphs: A survey and recent results, Discrete Math. 313 (2013) 839–854.
    https://doi.org/10.1016/j.disc.2012.11.031
  5. W. Goddard and M.A. Henning, Thoroughly dispersed colorings, J. Graph Theory 88 (2018) 174–191.
    https://doi.org/10.1002/jgt.22204
  6. T.W. Haynes, J.T. Hedetniemi, S.T. Hedetniemi, A.A. McRae and R. Mohan, Introduction to coalitions in graphs, AKCE Int. J. Graphs Comb. 17 (2020) 653–659.
    https://doi.org/10.1080/09728600.2020.1832874
  7. T.W. Haynes, J.T. Hedetniemi, S.T. Hedetniemi, A.A. McRae and R. Mohan, Upper bounds on the coalition number, Australas. J. Combin. 80 (2021) 442–453.
  8. T.W. Haynes, J.T. Hedetniemi, S.T. Hedetniemi, A.A. McRae and R. Mohan, Coalition graphs, Commun. Comb. Optim. 8 (2023) 423–430.
  9. T.W. Haynes, S.T. Hedetniemi and P.J. Slater, Fundamentals of Domination in Graphs (Boca Raton, CRC Press, 1998).
    https://doi.org/10.1201/9781482246582
  10. T.W. Haynes, S.T. Hedetniemi and P.J. Slater, Domination in Graphs: Advanced Topics (Marcel Dekker, New York, 1998).
    https://doi.org/10.1201/9781315141428
  11. M.A. Henning and A. Yeo, Total Domination in Graphs (Springer Monographs in Mathematics, 2013).
  12. M.A. Henning, A survey of selected recent results on total domination in graphs, Discrete Math. 309 (2009) 32–63.
    https://doi.org/10.1007/978-1-4614-6525-6

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