New posts in spectral-theory

Integral operator and it’s spectrum

Spectrum for a bounded linear operator and its adjoint on a Banach space are same.

Question on charaterization of the parts of the spectrum of an operator.

Normal Operators: Numerical Range

Show that $T f(x) = \frac{1}{x^2}\int\limits_0^x t f(t) dt$ is not compact.

Ratio of largest eigenvalue to sum of eigenvalues -- where to read about it?

How to understand the spectral decomposition geometrically?

Find the spectrum of $(Ff)(x)=\int_{-\pi}^{\pi} (1 + \cos(x-y))f(y)dy$

Resolvent: Definition

Spectral integral: reference request

Why do we distinguish the continuous spectrum and the residual spectrum?

Spectrum of shift-operator

How to prove the spectrum of the Laplace operator?

Proposition 1.4 in Takesaki's book "Theory of operator algebra": about the spectral integral

Spectral decomposition of compact self-adjoint operator

Space of linear, continuous, hyperbolic functions is open, dense in the set of invertible functions

Spectral integral: verification of my conceptual understanding

Intuition on spectral theorem

Spectrum of self-adjoint operator on Hilbert space real

Does an unbounded operator $T$ with non-empty spectrum have an unbounded spectrum?