Sakhnovich, A. L. Spectral functions of a canonical system of 2n-th order. (Russian) Zbl 0718.34112 Mat. Sb. 181, No. 11, 1510-1524 (1990). Summary: The set of pseudospectral functions of a canonical system of differential equations \(dW(x,\lambda)/dx=i\lambda JH(x)W(x,\lambda),\) \(W(0,\lambda)=E_{2n}\), is described, where \(0\leq x\leq \ell <\infty\), \(H(x)=H^*(x)\geq 0\), \(J=\left[ \begin{matrix} 0\\ E_ n\end{matrix} \begin{matrix} E_ n\\ 0\end{matrix} \right].\) In terms of the Hamiltonians H(x) conditions are given which guarantee that the pseudospectral functions are spectral ones. Cited in 2 ReviewsCited in 6 Documents MSC: 34L05 General spectral theory of ordinary differential operators Keywords:pseudospectral functions; Hamiltonians PDFBibTeX XMLCite \textit{A. L. Sakhnovich}, Mat. Sb. 181, No. 11, 1510--1524 (1990; Zbl 0718.34112) Full Text: EuDML