Alon–Boppana bound
= Alon–Boppana bound
{wiki=Alon–Boppana_bound}
The Alon–Boppana bound is a result in the field of graph theory and spectral graph theory. It provides a lower bound on the largest eigenvalue (also known as the spectral radius) of a regular graph. More formally, let \\( G \\) be a \\( d \\)-regular graph on \\( n \\) vertices.