Oscillation theorems for second-order forced neutral nonlinear differential equations with delayed argument (Q606221)

Summary: This paper concerns the oscillation of forced second-order neutral nonlinear differential equations with delayed argument of the form \[ (r(t)(x(t)+a(t)x(\sigma(t)))')'+p(t)f(x(\tau(t)))+\sum^n_{i=1} q_i(t)|x(t)|^{\lambda_i}\text{sng}\,x(t)=e(t). \] No restriction is imposed on the potentials \(p(t)\), \(q_i(t)\), and \(e(t)\) to be nonnegative. Our methodology is somewhat different from those of previous authors.