English

Vertex connectivity of chordal graphs

Combinatorics 2025-02-12 v1

Abstract

Let GG be a finite graph and κ(G)\kappa(G) the vertex connectivity of GG. A chordal graph GG is called chordal^* if no vertex of GG is adjacent to all other vertices of GG. Using the syzygy theory in commutative algebra, it is proved that every chordal^* graph GG on nn vertices satisfies κ(G)(n1)2n2\kappa(G) \leq (n - 1) - \lceil2\sqrt{n}-2\,\rceil. Furthermore, given an integer 0κ(n1)2n20 \leq \kappa \leq (n - 1) - \lceil2\sqrt{n}-2\,\rceil, a chordal^* graph GG on nn vertices satisfying κ(G)=κ\kappa(G) = \kappa is constructed.

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Cite

@article{arxiv.2502.07320,
  title  = {Vertex connectivity of chordal graphs},
  author = {Tài Huy Hà and Takayuki Hibi},
  journal= {arXiv preprint arXiv:2502.07320},
  year   = {2025}
}

Comments

4 pages, 1 figure