The strong spectral property for graphs

Abstract

We introduce the set $\mathcal{G}^{\rm SSP}$ of all simple graphs $G$ with the property that each symmetric matrix corresponding to a graph $G \in \mathcal{G}^{\rm SSP}$ has the strong spectral property. We find several families of graphs in $\mathcal{G}^{\rm SSP}$ and, in particular, characterise the trees in $\mathcal{G}^{\rm SSP}$.