Lethargy results in LTI system modelling
Modeling of linear time-invariant (LTI) systems is studied in an approximate modelling framework motivated by modern robust control theory. Many lethargy (negative) results are given an existence of coprime factorizations, on stabilization and on rational approximation. The relationship between \(H_\infty\) methods and bounded power signal spaces is studied. Different definitions of the important finite power signal setup are studied and new results given.
scientific article; zbMATH DE number 1325738