A Spectral Lower Bound on Chromatic Numbers using $p$-Energy

Clive Elphick, Quanyu Tang, Shengtong Zhang

Let $A_G$ be the adjacency matrix of a simple graph $G$, and let $\chi (G)$, ${\chi }_f(G)$, ${\chi }_q(G)$, $\xi (G)$ and ${\xi }_f(G)$ denote its chromatic number, fractional chromatic numb…