Research Article | | Peer-Reviewed

Strong Hub Sets and Strong Hub Number of Hypergraphs

Received: 29 October 2025     Accepted: 8 November 2025     Published: 15 January 2026
Views:       Downloads:
Abstract

This paper introduces and investigates the concepts of strong hub sets and the strong hub number in hypergraphs, extending the notion of hub sets defined for graphs. For a hypergraph H = (V, E), a subset S ⊆ V (H) is said to be a strong hub set if, for every pair of distinct vertices u, v ∈ V (H) − S, either u and v are adjacent or there exists a strong S-hyperpath joining them. The minimum cardinality of such a set is called the strong hub number of H, denoted by h∗(H). Fundamental properties of strong hub sets are established, and relationships between the strong hub number and various hypergraph parameters such as the domination number and connectivity are explored. The effects of vertex deletion and weak deletion on h∗(H) are studied, leading to several sharp bounds and recursive characterizations. In particular, it is shown that under weak deletion of a non cut vertex, the strong hub number remains invariant, while deletion of a cut vertex reduces it according to the structure of the resulting components. Special attention is devoted to hypertrees, where structural simplicity allows a precise characterization. This characterization provides an exact formula for h∗(H) in acyclic hypergraphs and establishes the foundational link between connectivity and hub-based path structure in hypertrees.

Published in American Journal of Applied Mathematics (Volume 14, Issue 1)
DOI 10.11648/j.ajam.20261401.11
Page(s) 1-9
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2026. Published by Science Publishing Group

Keywords

Strong Hub Set, Strong Hub Number, Hyperpath

References
[1] Acharya B., Domination in Hypergraphs, AKCE J. Graphs. Combin., 4 NO. 2 (2007), 111-126.
[2] M. Amin Bahmanian and Mateja Sajna, Hypergraphs: connection and separation., arXiv: 1504. 04274v2 [math.CO], 2 (28 May 2015).
[3] Amitesh Sarkar, Anirban Bnerjee., Joins of hypergraphs and their spectra., arXiv: 1912. 12921v1 [math CO], 1(30 Dec 2019).
[4] Berge C., Graphs and Hypergraphs, North-Holland, Amsterdam 6(1973).
[5] Berge C., Hypergraphs, North-Holland Mathematical Library, New York, Volume-45 (1989).
[6] Ioan Tomescu., On the chromaticity of sunflower hypergraphs SH(n,p,h)., Discrete Mathematics. 307 (2007), 781-786.
[7] Matthew Walsh, The hub number of a graph, International Journal of Mathematics and computer Science., 1 (2006), 117, 124.
[8] Regina I. Ttshkevich, Vadim E. Zverovich, Line hypergraphs : A survey, Acta Applicandae Mathematicae., 52 (1998), 209-222.
[9] K. K. Mythili, C. Nandhini, Hub parameters of Hypergraph, J. Indones. Math. Soc, 30 01 (2024), 100-109.
[10] V. I. Voloshin, Introduction to Graph and Hypergraph Theory, Nova Science Publishers, 2009.
[11] A. Bretto, Hypergraph Theory: An Introduction, Springer, 2013.
[12] C. Thomassen, Connectivity in hypergraphs, J. Combin. Theory Ser. B, 37(2) (1984), 244–249.
[13] I. E. Zverovich, On hypertrees and their applications in network theory, Discrete Math. Algorithms Appl., 11(3)(2019), 1950045.
[14] X. Zhang, Y. Li, Domination in hypergraphs and its applications, Discuss. Math. Graph Theory, 36(2)(2016), 325–340.
[15] K. S. Shama, P. M. Divya, and T. V. Ramakrishnan, A Study on Hub Sets in Hypergraphs, Int. J. Math. And Appl., vol. 13 (2) (2025), pp. 71–81.
Cite This Article
  • APA Style

    Syed, S. K., Veetil, R. T., Madhavan, D. P. (2026). Strong Hub Sets and Strong Hub Number of Hypergraphs. American Journal of Applied Mathematics, 14(1), 1-9. https://doi.org/10.11648/j.ajam.20261401.11

    Copy | Download

    ACS Style

    Syed, S. K.; Veetil, R. T.; Madhavan, D. P. Strong Hub Sets and Strong Hub Number of Hypergraphs. Am. J. Appl. Math. 2026, 14(1), 1-9. doi: 10.11648/j.ajam.20261401.11

    Copy | Download

    AMA Style

    Syed SK, Veetil RT, Madhavan DP. Strong Hub Sets and Strong Hub Number of Hypergraphs. Am J Appl Math. 2026;14(1):1-9. doi: 10.11648/j.ajam.20261401.11

    Copy | Download

  • @article{10.11648/j.ajam.20261401.11,
      author = {Shama Kochuthundiyil Syed and Ramakrishnan Thekkan Veetil and Divya Pookulath Madhavan},
      title = {Strong Hub Sets and Strong Hub Number of Hypergraphs
    },
      journal = {American Journal of Applied Mathematics},
      volume = {14},
      number = {1},
      pages = {1-9},
      doi = {10.11648/j.ajam.20261401.11},
      url = {https://doi.org/10.11648/j.ajam.20261401.11},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajam.20261401.11},
      abstract = {This paper introduces and investigates the concepts of strong hub sets and the strong hub number in hypergraphs, extending the notion of hub sets defined for graphs. For a hypergraph H = (V, E), a subset S ⊆ V (H) is said to be a strong hub set if, for every pair of distinct vertices u, v ∈ V (H) − S, either u and v are adjacent or there exists a strong S-hyperpath joining them. The minimum cardinality of such a set is called the strong hub number of H, denoted by h∗(H). Fundamental properties of strong hub sets are established, and relationships between the strong hub number and various hypergraph parameters such as the domination number and connectivity are explored. The effects of vertex deletion and weak deletion on h∗(H) are studied, leading to several sharp bounds and recursive characterizations. In particular, it is shown that under weak deletion of a non cut vertex, the strong hub number remains invariant, while deletion of a cut vertex reduces it according to the structure of the resulting components. Special attention is devoted to hypertrees, where structural simplicity allows a precise characterization. This characterization provides an exact formula for h∗(H) in acyclic hypergraphs and establishes the foundational link between connectivity and hub-based path structure in hypertrees.
    },
     year = {2026}
    }
    

    Copy | Download

  • TY  - JOUR
    T1  - Strong Hub Sets and Strong Hub Number of Hypergraphs
    
    AU  - Shama Kochuthundiyil Syed
    AU  - Ramakrishnan Thekkan Veetil
    AU  - Divya Pookulath Madhavan
    Y1  - 2026/01/15
    PY  - 2026
    N1  - https://doi.org/10.11648/j.ajam.20261401.11
    DO  - 10.11648/j.ajam.20261401.11
    T2  - American Journal of Applied Mathematics
    JF  - American Journal of Applied Mathematics
    JO  - American Journal of Applied Mathematics
    SP  - 1
    EP  - 9
    PB  - Science Publishing Group
    SN  - 2330-006X
    UR  - https://doi.org/10.11648/j.ajam.20261401.11
    AB  - This paper introduces and investigates the concepts of strong hub sets and the strong hub number in hypergraphs, extending the notion of hub sets defined for graphs. For a hypergraph H = (V, E), a subset S ⊆ V (H) is said to be a strong hub set if, for every pair of distinct vertices u, v ∈ V (H) − S, either u and v are adjacent or there exists a strong S-hyperpath joining them. The minimum cardinality of such a set is called the strong hub number of H, denoted by h∗(H). Fundamental properties of strong hub sets are established, and relationships between the strong hub number and various hypergraph parameters such as the domination number and connectivity are explored. The effects of vertex deletion and weak deletion on h∗(H) are studied, leading to several sharp bounds and recursive characterizations. In particular, it is shown that under weak deletion of a non cut vertex, the strong hub number remains invariant, while deletion of a cut vertex reduces it according to the structure of the resulting components. Special attention is devoted to hypertrees, where structural simplicity allows a precise characterization. This characterization provides an exact formula for h∗(H) in acyclic hypergraphs and establishes the foundational link between connectivity and hub-based path structure in hypertrees.
    
    VL  - 14
    IS  - 1
    ER  - 

    Copy | Download

Author Information
  • Department of Mathematical Sciences, Kannur University, Kannur, Kerala, India

  • Department of Mathematical Sciences, Kannur University, Kannur, Kerala, India

  • Department of Mathematical Sciences, Kannur University, Kannur, Kerala, India

  • Sections