Is T self adjoint and unitary?
32606
Is the operator $T((x_1,x_2,...,x_n))=(x_1,\frac{x_2}2,\frac{x_3}3,...)$ on $\ell^2$ self-adjoint and unitary
55067
Norm of self-adjoint operator
78755
If matrix $A$ is unitary and $B^2=A$, is $B$ necessarily unitary?
155123
Selfadjoint Operator: Basic Criterion
5506
Perturbation property of Orthonormal basis for Hilbert space
131906
"An operator is hermitian". Implications?
80623
Must $S$ be a unitary matrix?
23089
Differences between symmetric, Hermitian, self-adjoint, and essentially self-adjoint operators
77891
$(U\circ T)^{*} = T^{*}\circ U^{*}$
26125
Does the canonical commutation relation fix the form of the momentum operator?
117187
Uniqueness of the involution on a $C^*$-algebra
146099
Why is this true: The only orthogonal projection that is also unitary from $\Bbb C^n$ to $\Bbb C^n$ is the identity
54668
Proof for the completeness of eigenfunctions of a self-adjoint operator
119352
compact and self adjoint square root of an operator
133609
orthonormal system in a Hilbert space
59531
Do $T$-invariant subspaces necessarily have a $T$-invariant complement?
50130
$\operatorname{Aut}(V)$ is isomorphic to $S_3$