Forced oscillation of sublinear impulsive differential equations via nonprincipal solution

In this paper, we give new oscillation criteria for forced sublinear impulsive differential equations of the form (r(t)x′)′+q(t)|x|γ−1x=f(t),t≠θi;Δr(t)x′+qi|x|γ−1x=fi,t=θi, where γ∈(0,1), under the assumption that associated homogenous linear equation (r(t)z′)′+q(t)z=0,t≠θi;Δr(t)z′+qiz=0,t=θi is nonoscillatory.