English

The high order spectral extrema of $2K_r$-free graphs

Combinatorics 2026-04-22 v1

Abstract

In this paper, we determine the graphs with maximum value of the sum number from kk-clique spectral radius to (2r1)(2r-1)-clique spectral radius among all 2Kr2K_{r}-free graphs on nn vertices for rk r\le k and large nn. We also determine the graphs with maximum 33-clique spectral radius among all 2K32K_{3}-free graphs on nn vertices. Our results are spectral versions of some results on generalized Tur\'an numbers.

Keywords

Cite

@article{arxiv.2604.19409,
  title  = {The high order spectral extrema of $2K_r$-free graphs},
  author = {Changjiang Bu and Yifan Sun and Haotian Zeng},
  journal= {arXiv preprint arXiv:2604.19409},
  year   = {2026}
}