On the Existence of Configurations of Subspaces in a Hilbert Space with Fixed Angles

Natasha D. Popova, Yurii S. Samoilenko

For a class of $\ast$-algebras, where $\ast$-algebra $A_{\Gamma ,\tau }$ is generated by projections associated with vertices of graph $\Gamma$ and depends on a parameter $\tau$ $(0<\tau \le 1)$, we study…