Volume 6, Number 2, Summer 1998
OSCILLATION RESULTS FOR LINEAR DIFFERENTIAL
SYSTEMS OF SECOND ORDER
Abstract. We consider the second order differential
where P, Q and Y are n×n matrices with P(t), Q(t) continuous
symmetric matrix-valued functions, P(t) > 0. We obtain
a series of conditions in order for system (1) to be oscillatory.
Our results can be regarded as generalizations of the oscillation
criteria for scalar equations by Wintner, Hartman, Coles
and Willett, Olech, Opial and Wazewski. For the special case
that P(t) ≡ I, this paper covers and improves some results by
Butler, Erbe and Mingarelli.