Spectral problems for canonical systems of equations on the axis
Direct and inverse spectral problems on the axis \((-\infty, \infty)\) are investigated for the following system of integral equations \[ w(x,z) = E_{2m} + izJ \int_0^x [d\sigma(t)] w(x,z), \] with \(J = \left(\begin{smallmatrix} 0 & E_m\\ E_m & 0\end{smallmatrix}\right)\), \(E_m\) is the identity matrix of order \(m,\) \(\sigma (s)\) is a continuous monotone increasing matrix function of order \(2m \times 2m \) on the segment \([-l, l].\) The problem on the axis is reduced to the problem on the half-axis. Corresponding Weyl-Titchmarsh functions are studied.
scientific article; zbMATH DE number 1206246