Interval oscillation criteria for forced mixed nonlinear impulsive differential equations with variable delay

In this paper, the interval qualitative properties of a class of mixed nonlinear impulsive differential equations are studied. Under the hypothesis of delay σ(t) being variable, the ratio of functions x(t−σ(t)) and x(t) on each considered interval is estimated, then Riccati transformation and \omega functions are applied to obtain interval oscillation criteria. The results gained by Özbekler and Zafer (2011) for delay σ(t)=0 and by Guo et al. (2012) for delay σ(t) being nonnegative constant are developed.