English

The spectral radius of graphs with no intersecting odd cycles

Combinatorics 2022-04-04 v2

Abstract

Let Hs,t1,,tkH_{s,t_1,\ldots ,t_k} be the graph with ss triangles and kk odd cycles of lengths t1,,tk5t_1,\ldots ,t_k\ge 5 intersecting in exactly one common vertex. Recently, Hou, Qiu and Liu [Discrete Math. 341 (2018) 126--137], and Yuan [J. Graph Theory 89 (1) (2018) 26--39] determined independently the maximum number of edges in an nn-vertex graph that does not contain Hs,t1,,tkH_{s,t_1,\ldots ,t_k} as a subgraph. In this paper, we determine the graphs of order nn that attain the maximum spectral radius among all graphs containing no Hs,t1,,tkH_{s,t_1,\ldots ,t_k} for nn large enough.

Keywords

Cite

@article{arxiv.2106.00587,
  title  = {The spectral radius of graphs with no intersecting odd cycles},
  author = {Yongtao Li and Yuejian Peng},
  journal= {arXiv preprint arXiv:2106.00587},
  year   = {2022}
}

Comments

25 pages. This is the Journal Version. The problem raised at the end of our paper was recently solved by Chen, Liu and Zhang; see arXiv:2108.03895. The extremal spectral problem involving the intersecting cliques was also solved in another paper; see the joint work arXiv:2108.03587v2. arXiv admin note: text overlap with arXiv:1911.13082 by other authors