Let $G$ be a graph of order $n$ such that for each vertex $v$ there are two associated vectors, $f_v, g_v\in R^n$, where $uv\in E(G)$ if and only if $\langle f_u - f_v , g_u-g_v \rangle \ge 0$. [ISGCI][1] didn't discuss such a class. > Has this class of graphs been studied? What are their properties? Are they perhaps equivalent to some well-known graph class? [1]: http://www.graphclasses.org