How to prove that $[Z,\rho(A)]=0$ for all $A \in\mathfrak{sl}(2,\mathbb{C})$ and $Z$ is the Casimir operator.
102495
Proof that the Casimir invariant of a representation commutes with everything
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
87188
Prove that a square-integrable entire function is identically zero
65873
A proof for Atiyah-Macdonald Exercise I.21.iii
4015
Maclaurin Expansion for $e^{e^{z}}$ at $z=0$
34702
Show $|A + uv^T| = (1 + v^T A^{-1} u) |A|$
59804
Show that the plane $\{su+tv|s,t \in\Bbb R\}$ in $\Bbb R^3$ is equal to the null space of some element of $(\Bbb R^3)^{*}$.
18518
Proof of dilogarithm reflection formula $\zeta(2)-\log(x)\log(1-x)=\operatorname{Li}_2(x)+\operatorname{Li}_2(1-x)$
116427
$(c^{\mu}\partial_{\mu}-m)\phi(x)=0$ not Lorentz-invariant?
129750
Order of $SL_2(\mathbb{Z}/ n\mathbb{Z})$
5526
Prove that $ℤ[i]^*= \{1,-1,i,-i\}$
133500
For an outer measure $m^*$, does $m^*(E\cup A)+m^*(E\cap A) = m^*(E)+m^*(A)$ always hold?
91622
Help with proof that $\mathbb Z[i]/\langle 1 - i \rangle$ is a field.
68014
Prove that $\mathfrak{su}(2)$ is not isomorphic to $\mathfrak{sl}(2,\mathbb R)$
33891
If $\mathbf A$ and $\mathbf B$ are Hermitian, when does $\det(\mathbf A-\lambda\mathbf B)=0$ have only real roots?
86717
Completeness of $\langle \mathscr{C} [0, 1], \| \cdot \|_1 \rangle$
111814
Precise connection between complexification of $\mathfrak{su}(2)$, $\mathfrak{so}(1,3)$ and $\mathfrak{sl}(2, \mathbb{C})$