INTERVAL OSCILLATION OF SECOND-ORDER EMDEN-FOWLER NEUTRAL DELAY DIFFERENTIAL EQUATIONS

Employing Riccati techniques and the integral averaging method, we establish interval oscillation criteria for the second-order Emden-Fowler neutral delay differential equation [vertical bar x'(t)vertical bar(gamma-1)x'(t)]' + q(1)(t)vertical bar y(t - sigma)vertical bar(alpha-1)y(t - sigma) + q(2)(t)vertical bar y(t - sigma)vertical bar(beta-1)y(t - sigma) = 0, where t >= t(0) and x(t) = y(t) + p(t) y(t - tau). The criteria obtained here are different from most known criteria in the sense that they are based on information only on a sequence of subintervals of [t(0), infinity), rather than on the whole half-line. In particular, two interesting examples that illustrate the importance of our results are included.