Oscillation of first-order delay equations (Q803378)

The author studies the oscillation of first order delay differential equations using a method that parallels the use of Riccati equations in the study of the oscillation of second order ordinary differential equations without delay. The author gives an alternative proof of a comparison theorem first established by Kwong and Patula, obtains some results on the asymptotic behavior of nonoscillatory solutions, proves a new criterion that falls within a gap left open by established results, and confirms a conjecture raised by \textit{B. R. Hunt} and \textit{J. A. Yorke} [J. Differ. Equations 53, 139-145 (1984; Zbl 0571.34057)].