The authors deal with oscillation criteria for self-adjoint differential systems , where are symmetric matrices of real-valued functions and is an -dimensional vector. As a consequence of the general oscillation criterion for the following result is proved.
Theorem. Let be an integer. If
where stands for the largest eigenvalue, then the system is oscillatory.
If and are scalar quantities then this statement reduces to the oscillation criterion of I. V. Kamenev [Mat. Zametky 23, 249-251 (1978; Zbl 0386.34032)].