Integer eigenvalues of the $n$-Queens graph

Domingos M. Cardoso, Inês Serôdio Costa, Rui Duarte

The $n$-Queens graph, $\mathcal{Q}(n)$, is the graph obtained from a $n\times n$ chessboard where each of its $n^2$ squares is a vertex and two vertices are adjacent if and only if…