 Feshbach–Fano partitioning

Feshbach–Fano partitioning is a mathematical technique used in quantum mechanics, particularly in the context of scattering theory and the study of resonances. This method allows researchers to analyze and separate different contributions to the scattering amplitude in a way that makes it easier to understand the underlying physical processes. The method is named after Steven Feshbach and Ugo Fano, both of whom made significant contributions to the understanding of resonances and scattering in quantum systems.