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Oscillation of first-order delay equations. (English) Zbl 0727.34064
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 B. R. Hunt and J. A. Yorke [J. Differ. Equations 53, 139-145 (1984; Zbl 0571.34057)].
MSC:
34K99Functional-differential equations
34C10Qualitative theory of oscillations of ODE: zeros, disconjugacy and comparison theory