Refined inertias of tree sign-patterns
Refined inertias of tree sign-patterns
The refined inertia (n + , n -, nz, 2np) of a real matrix is the ordered 4-tuple that subdivides the number n 0 of eigenvalues with zero real part in the inertia (n + , n -, n 0 ) into those that are exactly zero (nz) and those …