Orthonormal representation of a graph
= Orthonormal representation of a graph
= Orthonormal representation
{synonym}
Assign a real unit vector $u_v$ to each graph vertex, with $u_v\perp u_w$ whenever distinct vertices are nonadjacent. A handle is a further unit vector $h$. In the handle formulation of the <Lovász number>, one minimizes $\max_v|h\cdot u_v|^{-2}$ over representations and handles. Orthonormal here does not mean every pair of assigned vectors is orthogonal.