On the frequency of complex zeros of solutions of certain differential equations (Q1209427)

The paper treats equations of the form \(w^{(k)}+\sum^{k-1}_{j=1} Q_ j w^{(j)}+(Q_ 0+Re^ p)w=0\), where \(Q_ j\), \(R\), \(P\in\mathbb{C}[z]\). Under some condition, it is proved that the zero-sequence of any non-zero solution has an infinite exponent of convergence.