Аңдатпа
Abstract The paper gives a correct definition of the formal Laplace operator with delta-shaped perturbation. To define the area of use, the limiting potentials of simple and double layers are used. It is proved that from a set of spectra of some reference operators it is possible to unambiguously reconstruct the boundary densities of the potentials and the double layer. Moreover, one of the reference operators coincides with the original Laplace operator with delta-like perturbation.