Tight Bound for Nikiforov's Spectral Even-Cycle Conjecture

Peiru Kuang, Feng Liu, Shuang Sun +2

Nikiforov conjectured that, for every fixed $k\ge 2$ and all sufficiently large $n$, the unique $n$-vertex $C_{2k+2}$-free graph with maximum adjacency spectral radius is $S^+_{n,k}…