The inverse spectral problem for differential operators with nonseparated boundary conditions (Q1588430)

The paper is devoted to the study of the inverse spectral problem for the selfadjoint operator \(L=L(q(x), a,d,b)\), \(q\in L^2(0;\pi)\), \(a,d,b\in\mathbb{R}\), generated by the differential expression \(ly=-y''+qy\) and the nonseparated boundary conditions \(y'(0)-ay(0) +by(\pi)=0\), \(y'(\pi)+ dy(\pi)-by(0)=0\). A stability and a uniqueness theorem on the solution to the inverse problem are proved. A characterization of the spectrum of \(L\) and the solution to the inverse problem are also given.