Spectrum of an Operator(redirected from Spectrum (functional analysis))
Also found in: Wikipedia.
Spectrum of an Operator
The spectrum of the linear operator T is the set of numbers T for which the operator TʎE, where E is the identity operator, does not have an every where defined bounded inverse. The concept of the spectrum of an operator is a generalization of the concept of the set of eigenvalues of a matrix and is especially important for self-adjoint and unitary operators.