English

On a bipartite graph defined on groups

Group Theory 2024-12-10 v1 Combinatorics

Abstract

Let GG be a group and L(G)L(G) be the set of all subgroups of GG. We introduce a bipartite graph B(G)\mathcal{B}(G) on GG whose vertex set is the union of two sets G×GG \times G and L(G)L(G), and two vertices (a,b)G×G(a, b) \in G \times G and HL(G)H \in L(G) are adjacent if HH is generated by aa and bb. We establish connections between B(G)\mathcal{B}(G) and the generating graph of GG. We also discuss about various graph parameters such as independence number, domination number, girth, diameter, matching number, clique number, irredundance number, domatic number and minimum size of a vertex cover of B(G)\mathcal{B}(G). We obtain relations between B(G)\mathcal{B}(G) and certain probabilities associated to finite groups. We also obtain expressions for various topological indices of B(G)\mathcal{B}(G). Finally, we realize the structures of B(G)\mathcal{B}(G) for the dihedral groups of order 2p2p and 2p22p^2 and dicyclic groups of order 4p4p and 4p24p^2 (where pp is any prime) including certain other small order groups.

Keywords

Cite

@article{arxiv.2412.05494,
  title  = {On a bipartite graph defined on groups},
  author = {Shrabani Das and Ahmad Erfanian and Rajat Kanti Nath},
  journal= {arXiv preprint arXiv:2412.05494},
  year   = {2024}
}

Comments

23 pages

R2 v1 2026-06-28T20:26:20.815Z