Vector Coloring the Categorical Product of Graphs

Chris Godsil, David E. Roberson, Brendan Rooney +2

A vector $t$-coloring of a graph is an assignment of real vectors $p_1,\dots ,p_n$ to its vertices such that $p_i^T{p}_i=t-1$ for all $i=1,\dots ,n$ and $p_i^T{p}_j\le -1$ whene…