Using new techniques of spectral analysis EU-funded mathematicians were able to answer some outstanding questions in the non-self-adjoint extension of singular differential operators.
Until the 1960s, the spectral analysis of non-self-adjoint operators that appear, for example, in phenomenological models of nuclear scattering remained to a large extent terra incognita. The spectrum structure of one-dimensional and three-dimensional Schröedinger operators were known, but there were many difficulties in the study of these operators.
Further details: Mathematical aspects of physics