International Conference on Differential and Difference Equations and Applications, Ponta-Delgada, Portugal, 4 - 08 July 2011, vol.47, pp.183-195
In this paper we give new oscillation criteria for a class of second-order mixed nonlinear impulsive differential equations having fixed moments of impulse actions. The method is based on the existence of a nonprincipal solution of a related second-order linear homogeneous equation.