New posts in Operator Theory

Showing that $0\leq A\leq B$ and $B \in \mathcal{L}_c(H)$ implies that $A \in \mathcal{L}_c(H)$.

Is the limit of the spectral radius the spectral radius of the limit?

Is $0$ the only vector in the kernel of every bounded linear functional?

Computing the product $(\frac{d}{dx}+x)^n(-\frac{d}{dx}+x)^n$

Suppose $A,B$ are positive operators with $AB=0$,what is the norm of $A+B$?

Example of a non-trace class operator

Value of operator norm when $\mathcal{T}f(x)=\int^{x}_{0} f(t)dt$

Why is the magnetic Schrödinger operator positive?

$T: L^2[0,1] \to L^2[0,1]$, $Tf(x)= \frac{1}{x}\int_{0}^x f(y)$, is a bounded but not compact operator.

Does the inclusion $A \subset B$ for closed densely defined operators $A$ and $B$ imply $A=B$?