Let be $\sigma=(1\cdots n) \in S_n$. Then $C_{S_{n}}(\sigma) = \langle \sigma \rangle$.
14861
If $\sigma\in S_n$ is of length $n$, then $\sigma$ generates its centralizer
83220
If $U$ is unitary operator then spectrum $\sigma(U)$ is contained inside the unit circle
18839
Proof about inner product space $\vert \langle x,y\rangle \vert=\Vert x \Vert\Vert y \Vert$
29637
$\sigma$-algebra of sets that are both $G_\delta$ and $F_\sigma$
110450
probability measure on $\sigma$-algebra
115258
Find all positive integers $n$ such that $\phi(n)+\sigma(n)=2n$.
64118
Number of elements in a finite $\sigma$-algebra
1712
$ d_1,d_2\mid n\iff {\rm lcm}(d_1,d_2)\mid n\ $ [LCM Universal Property]
44575
The sigma function (sum of divisors) multiplicative proof
83183
Why is $\langle x| x' \rangle=\delta(x-x')$?
57166
Showing that $\Bbb R[x] / \langle x^2 + 1 \rangle$ is isomorphic to $\Bbb C$ question
120273
Showing that a collection of sets is a $\sigma$-algebra: either set or complement is countable
132725
Is $\mathbb{Z}/\langle n\rangle$ cyclic and of order $n$?
83830
Sigma algebra generated by the set of all singletons
68512
$\sigma$ algebra of collection of random variables
37346
If $m, n$ be positive integers, prove that $\phi(mn)=\phi((m,n))\phi([m,n])$, where $(m,n)=$ gcd of $m, n$ and $[m, n]=$ lcm of $m, n$.
151721
Uhlmann's Theorem: proof of $\text{tr}(A^{\dagger} B) = \langle m | A \otimes B |m\rangle $