Summability methods for oscillation of linear second-order matrix differential equations (Q1335203)

The oscillation criteria of Wintner and Hartman for the equation \(Y''+ q(t)y=0\) on \([0,\infty)\) using limits of the mean \((1/t)\int^ t_ 0\left(\int^ s_ 0 q(u)du\right)ds\) have been extended in many ways. Other extensions of the scalar results have been made to the matrix equation \(Y''+ Q(t)= 0\) and to the selfadjoint matrix equation (1) \((PY')'+ Q(t)Y= 0\). The authors combine all these results to obtain improved results for (1).