Nordhaus-Gaddum inequality for the spectral radius of a graph of order $n$
Yen-Jen Cheng, Chih-wen Weng·2025-06-13·via math.CO updates on arXiv.org
We determine the extremal graph $G$ of order $n$ that maximizes the sum of the spectral radii of $G$ and its complement. This resolves a conjecture posed by Stevanović in 2007.