English

DQ-integral and DL-integral generalized wheel graphs

Combinatorics 2024-01-11 v1

Abstract

A graph G is said to be M-integral (resp. A-integral, D-integral, DL-integral or DQ-integral) if all eigenvalues of its matrix M (resp. adjacency matrix A(G), distance matrix D(G), distance Laplacian matrix DL(G) or distance signless Laplacian matrix DQ(G)) are integers. Lu et al. [Discrete Math, 346 (2023)] defined the generalized wheel graph GW(a, m, n) as the join of two regular graphs aKm and Cn, and obtained all D-integral generalized wheel graphs. Based on the above research, in this paper, we determine all DL-integral and DQ-integral generalized wheel graphs respectively. As byproducts, we give a sufficient and necessary condition for the join of two regular graphs G1 and G2 to be DL-integral, from which we can get infinitely many new classes of DL-integral graphs according to the large number of research results about the A-integral graphs.

Keywords

Cite

@article{arxiv.2401.05059,
  title  = {DQ-integral and DL-integral generalized wheel graphs},
  author = {Yirui Chai and Ligong Wang and Yuwei Zhou},
  journal= {arXiv preprint arXiv:2401.05059},
  year   = {2024}
}
R2 v1 2026-06-28T14:13:05.059Z