The inverse spectral problem for the discrete cubic string

Jennifer Kohlenberg, Hans Lundmark, Jacek Szmigielski

Given a measure $m$ on the real line or a finite interval, the "cubic string" is the third order ODE $-{\varphi }^{\prime \prime \prime }=zm\varphi$ where $z$ is a spectral parameter. If equipped with Dirichlet-like…