A characterization of some subsets of Schechter's essential spectrum and application to singular transport equation

Linear Operators. Part I: General Theory.

Paul Civin, Nelson Dunford, J. T. Schwartz · American Mathematical Monthly · 1960 · 2.8K citations

Linear Operator, Linear System, Matrix Theory +2

Perturbation theory for nullity, deficiency and other quantities of linear operators

Tosio Kato · Journal d Analyse Mathématique · 1958 · 520 citations

Spectral Theory, Linear Operator, Engineering +8

Oper. Theory Adv. Appl.

Seppo Hassi, H. S. V. de Snoo · 2006 · 319 citations

Automated Reasoning, Theory Building, Theory Adv +1

On the essential spectrum of an arbitrary operator. I

Martin Schechter · Journal of Mathematical Analysis and Applications · 1966 · 166 citations

Spectral Theory, Linear Operator, Engineering +4

On the essential spectrum of partial differential boundary problems

František Wolf · Communications on Pure and Applied Mathematics · 1959 · 135 citations

Riemann-hilbert Problem, Calculus Of Variation, Essential Spectrum +1