Oscillation results for matrix differential systems with damping

In this paper, we establish several new oscillation theorems of Leighton type for the matrix differential system with damping (P(t)Y′)′ + R(t)Y′ + Q(t)Y = 0 under the hypothesis: P(t) = P∗(t) > 0, Q(t) = Q∗(t) and R(t) = R∗(t) are n × n matrices of real valued continuous functions on the interval [t0, ∞). Our results are not contained in known results.