Inverse problems for Sturm-Liouville differential operators with two constant delays under Robin boundary conditions

This paper deals with non-self-adjoint second-order differential operators with two constant delays from [pi/2, pi) and two potentials from L-2 [0, pi]. We study the inverse spectral problem of recovering operators from their spectra. Four boundary value problems under Robin boundary conditions are considered. It has been proved that delays and the Fourier coefficients of potentials are uniquely determined from the spectra. Finally, potentials are constructed. (C) 2019 The Author(s). Published by Elsevier B.V.