Category:Operator theory

D

• Differential operators (1 C, 55 P)

F

• Fredholm theory (15 P)
• Functional calculus (4 P)

I

• Invariant subspaces (10 P)

L

• Linear operators (8 C, 47 P)

O

• Operator theorists (44 P)

Q

• Quantum operators (15 P)

S

• Singular value decomposition (13 P)
• Spectral theory (53 P)

U

• Unitary operators (11 P)

• Gap metric
• Operator theory

+

• + h.c.

A

• Affiliated operator
• Antieigenvalue theory
• Approximation property
• AW*-algebra

B

• Banach–Stone theorem
• Beltrami equation
• Berezin transform
• Bergman space
• Birman–Schwinger principle
• Bounded operator
• Browder–Minty theorem

C

• Calderón projector
• Calkin algebra
• Cauchy–Schwarz inequality
• Choi's theorem on completely positive maps
• Cholesky decomposition
• Commutant lifting theorem
• Compact operator
• Compact operator on Hilbert space
• Composition operator
• Continuous linear operator
• Contraction (operator theory)
• Controlled invariant subspace
• Convexoid operator
• Cotlar–Stein lemma
• Crossed product
• Cyclic and separating vector

D

• De Branges space
• Densely defined operator
• Differential operator
• Dilation (operator theory)
• Discrete Laplace operator
• Dissipative operator
• Dixmier trace
• Douglas' lemma

E

• Eigenvalues and eigenvectors of the second derivative
• Extensions of symmetric operators

F

• Farrell–Markushevich theorem
• Finite-rank operator
• Friedrichs extension
• Fuglede's theorem

G

• Gelfand representation
• Gelfand–Naimark theorem
• Grunsky matrix

H

• Hardy space
• Harmonic tensors
• Hermitian adjoint
• Hilbert C*-module
• Hilbert space
• Hilbert–Schmidt integral operator
• Hilbert–Schmidt operator
• Hilbert–Schmidt theorem
• Hypercyclic operator
• Hyponormal operator

I

• Indefinite inner product space
• Index group
• Integration by parts operator
• International Workshop on Operator Theory and its Applications
• Invariant subspace
• Invariant subspace problem

J

• Jacobi operator
• Jordan operator algebra

K

• Kato's conjecture
• Kronecker sum of discrete Laplacians
• Krylov subspace
• Kuiper's theorem

L

• Limiting absorption principle
• Limiting amplitude principle
• Linear subspace
• Liouville space
• Littlewood subordination theorem
• Lomonosov's invariant subspace theorem

M

• Min-max theorem
• Multiplication operator
• Multipliers and centralizers (Banach spaces)
• Mutually unbiased bases

N

• Naimark's dilation theorem
• Nemytskii operator
• Nest algebra
• Neumann–Poincaré operator
• Nilpotent operator
• Normal operator
• Nuclear C*-algebra
• Nuclear operator
• Nuclear operators between Banach spaces
• Nuclear space
• Numerical range

O

• Operator (physics)
• Operator algebra
• Operator monotone function
• Operator norm
• Operator space
• Operator system
• Ornstein–Uhlenbeck operator
• Oscillator representation

P

• Paranormal operator
• Partial isometry
• Polar decomposition
• Positive-definite kernel
• Positive operator
• Positive-definite function on a group
• Product numerical range
• Pseudo-monotone operator

Q

• Quasinormal operator

R

• Real rank (C*-algebras)
• Reflexive operator algebra
• Resolvent set
• Riesz–Thorin theorem

S

• Schatten class operator
• Schatten norm
• Schröder–Bernstein theorems for operator algebras
• Sectorial operator
• Titu's lemma
• Self-adjoint operator
• Sherman–Takeda theorem
• SIC-POVM
• Singular integral operators of convolution type
• Singular integral operators on closed curves
• Singular value
• Sobolev spaces for planar domains
• Spectral theory of ordinary differential equations
• Stein–Strömberg theorem
• Stinespring dilation theorem
• Strictly singular operator
• Sturm–Liouville theory
• Subfactor
• Subnormal operator
• Symmetric operator
• Symmetrizable compact operator
• Sz.-Nagy's dilation theorem

T

• Tensor product of Hilbert spaces
• Toeplitz operator
• Tomita–Takesaki theory
• Topological tensor product
• Trace class
• Trace inequality
• Trace operator
• Transfer operator
• Tree kernel

U

• Unbounded operator
• Uniformly bounded representation
• Unilateral shift operator
• Unitary operator

V

• Volterra operator
• Von Neumann algebra
• Von Neumann bicommutant theorem
• Von Neumann's inequality
• Von Neumann's theorem

W

• Weyl–von Neumann theorem
• Wold's decomposition
• Workshop on Numerical Ranges and Numerical Radii