47A64 Operator means, shorted operators, etc.

47A66 Quasitriangular and nonquasitriangular, quasidiagonal and nonquasidiagonal operators

47A68 Factorization theory (including Wiener-Hopf and spectral factorizations)

47A70 (Generalized) eigenfunction expansions; rigged Hilbert spaces

47A75 Eigenvalue problems [See also <a href="#code:47J10">47J10</a>, <a href="#code:49R05">49R05</a>]

47A80 Tensor products of operators [See also <a href="#code:46M05">46M05</a>]

47A99 None of the above, but in this section

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, $p$-summing, in the Schatten-von Neumann classes, etc.) [See also <a href="#code:47L20">47L20</a>]

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 reproducing-kernel Hilbert spaces (including de Branges, de Branges-Rovnyak, and other structured spaces) [See also <a href="#code:46E22">46E22</a>]

47B35 Toeplitz operators, Hankel operators, Wiener-Hopf operators [See also <a href="#code:45P05">45P05</a>, <a href="#code:47G10">47G10</a> for other integral operators; see also <a href="#code:32A25">32A25</a>, <a href="#code:32M15">32M15</a>]

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 <a href="#code:39A70">39A70</a>]

47B40 Spectral operators, decomposable operators, well-bounded operators, etc.

47B44 Accretive operators, dissipative operators, etc.

47B47 Commutators, derivations, elementary operators, etc.

47B49 Transformers, preservers (operators on spaces of operators)