A question about commutativity of linear operators
57731
Can commuting matrices $X,Y$ always be written as polynomials of some matrix $A$?
25430
When is matrix multiplication commutative?
3038
For positive invertible operators $C\leq T$ on a Hilbert space, does it follow that $T^{-1}\leq C^{-1}$?
136909
Functional Analysis: The rank of an operator detemines if it's a compact operator.
80346
If every eigenvector of $T$ is also an eigenvector of $T^{*}$ then $T$ is a normal operator
52791
Invertibility of an operator $T$ if $\|I-T\|<1$
103142
Question on equivalence of inner product
108781
$A$ and $B$ are bounded linear operators from the normed linear space $X$ to itself. If $AB$ is invertible are $A$ and $B$ invertible?
17031
Idempotent linear operators are projections
28485
Commutativity of projection and rotation
77891
$(U\circ T)^{*} = T^{*}\circ U^{*}$
66134
Sufficiently many idempotents and commutativity
56211
An operator that commutes with another operator $T$ with distinct characteristic values is a polynomial in $T$
51302
Show that the operator norm is submultiplicative
37867
If $0$ is the only eigenvalue of a linear operator, is the operator nilpotent
128457
Show that $T$ is a compact operator
18817
Does commutativity imply Associativity?