An oscillation criterion for second order sublinear differential equations (Q1206968)

The differential equation under consideration is (1) \(-y''=pf(y)\), where \(p\in C[0,\infty)\), \(f\in C(-\infty,\infty)\), \(yf(y)>0\) for \(y\neq 0\), \(f\) is nondecreasing, and \(f\) satisfies a general sublinearity condition. The main theorem is a sufficient condition for all continuable solutions of (1) to be oscillatory at \(\infty\). This generalizes earlier results of Y. Chen, I. V. Kamenev, Ch. G. Philos, and the first author, mostly for the case \(f(y)=| y|^ a\text{ sgn }y\), \(0<a<1\).