A simple oscillation criteria for second-order differential equations with piecewise constant argument of generalized type
Ricardo Torres Naranjo
TL;DR
The paper addresses the problem of establishing simple, verifiable oscillation criteria for second-order differential equations with a generalized piecewise constant argument (DEPCAG). It develops two Leighton-Wintner-type oscillation criteria for the DEPCAG $(r(t)x'(t))'+f(t,x(\\gamma(t)))=0$ by leveraging a key lemma that enforces monotone behavior of $x'(t)$ under integral conditions on $r$, and by analyzing the auxiliary quantity $w(t)=\\frac{r(t)x'(t)}{\\phi(x(\\gamma(t)))}$ across advanced and delayed subintervals. The main contributions are two criteria: (i) a criterion requiring $\\int_{\\tau}^{\\infty} p(s) ds=\\infty$, and (ii) a second criterion based on mixed integrability conditions involving $\\phi$, $p$, and $r$, with a generalized $\\gamma(t)$ that recovers the classical Wang-Cheng results when $\\gamma(t)=[t]$. These results yield simple, checkable oscillation conditions for DEPCAG models exhibiting hybrid continuous-discrete dynamics, and the paper illustrates applicability with linear and nonlinear examples.
Abstract
This work presents two simple criteria for determining the oscillatory nature of solutions to second-order differential equations with deviated arguments. These criteria extend the (Leighton-Wintner)-type criteria established by G.Q. Wang and S.S. Cheng, considering a generalized piecewise constant argument. Finally, we provide some examples.
