Spectral extremal problems on planar and outerplanar graphs without $C_{k,l}

Jiamin Li, Dan Li, Xilong Yin +1

Let ${\text{spex}}_{\mathcal{P}}(n,F)$ and ${\text{spex}}_{\mathcal{O}\mathcal{P}}(n,F)$ be the maximum spectral radius among all $n$-vertex $F$-free planar graphs and outerplanar graphs, respec…