New posts in Operator Norms

$\sup \left\| A x + B y\right\|_2$ subject to $\left\|x\right\|_2 = \left\|y\right\|_2 = 1$

Norm estimation of identity plus two non-commuting self-adjoint operators

Bounding the matrix norm of a commutator $[A,B]$ in terms of the norms of $A$ and $B$

Equivalence between complex and real operator norms

Norm of $n$-linear symmetric forms

Hölder's inequality for matrices