English

Eccentricity spectral properties of $\mathcal{C}$-graphs

Combinatorics 2025-09-23 v1

Abstract

A cograph is a simple graph that contains no induced path on four vertices. In this paper, we consider C\mathcal{C}-graphs, which are a specific class of cographs, defined as Kα1Kα2Kα2k,\overline{\overline{\overline{K_{\alpha_{1}}}\cup K_{\alpha_{2}}}\cup \cdots \cup K_{\alpha_{2k}}}, %\text{ where } k \geq 2, \alpha_{2k}\geq 2, where k2k \geq 2, α2k2\alpha_{2k} \geq 2, and KαiK_{\alpha_{i}} denotes the complete graph on αi\alpha_{i} vertices. We investigate the spectral properties of the eccentricity matrix of this particular class of cographs. Additionally, we determine the irreducibility and inertia of the eccentricity matrix of C\mathcal{C}-graphs. Furthermore, we identify an interval (12,2)(2,0)(-1-\sqrt{2},-2)\cup (-2,0) in which these graphs have no eccentricity eigenvalues.

Keywords

Cite

@article{arxiv.2509.16657,
  title  = {Eccentricity spectral properties of $\mathcal{C}$-graphs},
  author = {Anjitha Ashokan and Chithra A},
  journal= {arXiv preprint arXiv:2509.16657},
  year   = {2025}
}
R2 v1 2026-07-01T05:47:14.077Z