$\operatorname{spectrum}(AB) = \operatorname{spectrum}(BA)$?
129007
Relation between AB and BA
123555
Proving that if $ab=e$ then $ba=e$
68449
$\operatorname{Supp}(M)=V(\operatorname{Ann}M)$ if $M$ is finitely generated
55062
$2\times 2$ matrix $C=AB-BA$
110944
Proving that $AB-BA=cI$ for nontrivial $c \in \mathbb{C}$
127000
When does $V = \ker(f) \oplus \operatorname{im}(f)$?
55488
Proving that $\operatorname{codim}(X,Y)=\dim(\mathcal{O}_{X,\eta})$
76200
Is the rank of $AB$ always equal to the rank of $BA$?
13971
find spectrum matrix A
43000
Show $\operatorname{rank}(A) + \operatorname{rank}(B) \ge \operatorname{rank}(A+B)$
150704
Do the ladder operators $a$ and $a^\dagger$ form a complete algebra basis?
118310
How to find $\operatorname{Gal}(S/\mathbb{Q})$
50384
A matrix and its transpose have the same set of eigenvalues/other version: $A$ and $A^T$ have the same spectrum
27821
A problem on rank of $A$ and $\operatorname{adj}(A)$
2635
equality of two operators...
23115
Why is the spectrum of the $\beta$-decay continuous?
106097
Spectrum of the sum of two commuting matrices