https://doi.org/10.1051/epjconf/202328704023
Resonant State Spectral expansions including bound-state contributions
Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, 13397 Marseille, France
* e-mail: brian.stout@fresnel.fr
Published online: 18 October 2023
Extensions of the Resonant State or (Quasi-normal mode) formalism are shown to permit unified descriptions of the true ’bound’ states within the framework of the ’leaky’ mode formulation of basis sets. We review recent progress in the famed ’normalization/regularization’ problems of the QNMs modes as well as the necessity of including ’background’ contributions whose expressions can be determined through response function sum-rules.
© The Authors, published by EDP Sciences, 2023
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
