## Mathematics Subject Classification – MSC2010

Linear relations (multivalued linear operators) 359

Several-variable operator theory (spectral, Fredholm, etc.) 913

Operator colligations (= nodes), vessels, linear systems, characteristic functions, realizations, etc. 387

(Semi-) Fredholm operators; index theories [See also 58B15, 58J20 (Semi-) Fredholm operators; index theories [See also 58B15, 58J20] 3418

Functions whose values are linear operators (operator and matrix valued functions, etc., including analytic and meromorphic ones) 1887

Factorization theory (including Wiener-Hopf and spectral factorizations) 1039

(Generalized) eigenfunction expansions; rigged Hilbert space (Generalized) eigenfunction expansions; rigged Hilbert spaces 1511