Spectrum dichotomy and a stability criterion for sectorial operators
The discussion of this paper, based on the familiar facts from the theory of linear operators, justifies criteria for the possibility of distinguishing low-dimensional invariant subspaces from whose spectra we can judge stability or instability. In the paper, some specially constructed condition number is used and the additional requirement on the operator which is sectorial is supposed.
scientific article; zbMATH DE number 917155