New results on oscillation for delay differential equations with piecewise constant argument

We introduce a new technique to obtain some new oscillation criteria for the oscillating coefficients delay differential equation with piecewise constant argument of the form x'(t) + a(t)x(t) + b(t)x([t - kj) = 0, where a(t) and b(t) are right continuous functions on [-k, infinity), k is a positive integer, and [.] denotes the greatest integer function. Our results improve and generalize the known results in the literature. Some examples are also given to demonstrate the advantage of our results. (C) 2003 Elsevier Science Ltd. All rights reserved.