Mishnaevskij, P. A. Length of the gaps in the continuous spectrum of the Sturm-Liouville operator. (Russian) Zbl 0586.34020 Differ. Uravn. 21, No. 6, 1095-1097 (1985). The operator \(-d^ 2/dx^ 2+q(x)\) (and its natural generalizations) is considered in spaces \(L_ 2({\mathbb{R}}_+)\) or \(L_ 2({\mathbb{R}})\). Different bounds on the length of gaps in its continuous spectrum are given in terms of the smoothness of q. Reviewer: D.Yafaev MSC: 34L99 Ordinary differential operators Keywords:second order differential equation PDFBibTeX XMLCite \textit{P. A. Mishnaevskij}, Differ. Uravn. 21, No. 6, 1095--1097 (1985; Zbl 0586.34020)