Classification of joint numerical ranges of three hermitian matrices of size three

Konrad Szymański, Stephan Weis, Karol Życzkowski

The joint numerical range $W(F)$ of three hermitian $3$-by-$3$ matrices $F=(F_1,F_2,F_3)$ is a convex and compact subset in ${\mathbb{R}}^3$. Generically we find that $W(F)$ is a thr…