Double dual of the space of bounded operators on Hilbert space
54377
Complementability of von Neumann algebras
144112
Show that $c_0$ is a Banach space with the norm $\rVert \cdot \lVert_\infty$
128361
The kernel and range of the powers of a self-adjoint operator
83970
Proof of an elementary property of Projection Operators
118564
Dual cone of a $L^1$ norm cone?
60685
The vector space formed on C[0,1] and the norm $(\int_{0}^{1}|f(t)|^2 dt)^{1/2} $
42941
Pair of adjoint functors and showing that two certain maps are inverses
139272
On the norm of a quotient of a Banach space.
119352
compact and self adjoint square root of an operator
14550
Every Hilbert space has an orthonomal basis - using Zorn's Lemma
145222
The dual of subspace of a normed space is a quotient of dual: $X' / U^\perp \cong U'$
125277
Image of the tensor product of strict maps of Banach spaces
34173
Banach spaces and their unit sphere
90757
$T$ self-adjoint on Hilbert space $H$, $T^n=T^{n+1}$ will $T$ be an orthogonal projection operator?
55533
Tensor Product: Hilbert Spaces
88535
Relation between the distance from a point to the resolvent set of a self-adjoint operator and the norm of a related operator
63104
Dual cone of $K = \{(x,t) \mid \| \boldsymbol{x} \|_1 \le t \}$