47Bxx Special classes of linear operators
 47B06 Riesz operators; eigenvalue distributions; approximation numbers, s numbers, Kolmogorov numbers, entropy numbers, etc. of operators
 47B07 Operators defined by compactness properties
 47B10 Operators belonging to operator ideals (nuclear, psumming, in the Schattenvon Neumann classes, etc.) [See also 47L20]
 47B15 Hermitian and normal operators (spectral measures, functional calculus, etc.)
 47B20 Subnormal operators, hyponormal operators, etc.
 47B25 Symmetric and selfadjoint operators (unbounded)
 47B32 Operators in reproducingkernel Hilbert spaces (including de Branges, de BrangesRovnyak, and other structured spaces) [See also 46E22]
 47B33 Composition operators
 47B34 Kernel operators
 47B35 Toeplitz operators, Hankel operators, WienerHopf operators [See also 45P05, 47G10 for other integral operators; see also 32A25, 32M15]
 47B36 Jacobi (tridiagonal) operators (matrices) and generalizations
 47B37 Operators on special spaces (weighted shifts, operators on sequence spaces, etc.)
 47B38 Operators on function spaces (general)
 47B39 Difference operators [See also 39A70]
 47B40 Spectral operators, decomposable operators, wellbounded operators, etc.
 47B44 Accretive operators, dissipative operators, etc.
 47B47 Commutators, derivations, elementary operators, etc.
 47B48 Operators on Banach algebras
 47B49 Transformers, preservers (operators on spaces of operators)
 47B50 Operators on spaces with an indefinite metric [See also 46C50]
 47B60 Operators on ordered spaces
 47B65 Positive operators and orderbounded operators
 47B80 Random operators [See also 47H40, 60H25]

47B99 None of the above, but in this section
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