How can $\hat p = - i \hbar \partial_q$ be derived starting from the definitions of $\hat q$ and $\hat p$ in terms of creation/destruction operators?
59021
What is the most general expression for the coordinate representation of momentum operator?
126425
Consistent, complete, and generalized description of the quantum harmonic oscillator
26125
Does the canonical commutation relation fix the form of the momentum operator?
108657
Cross product of the quantum mechanical operators $\textbf{p}$ and $\textbf{A}$
73624
Why is orbital angular momentum quantized according to $I= \hbar \sqrt{\ell(\ell+1)}$?
139631
How to take this exterior derivative of the expression $du - \sum_i p_i dx_i$?
27086
proof for $\langle q| p \rangle = e^{ipq}$
78592
Tensor product of Hadamard operators
83970
Proof of an elementary property of Projection Operators
12422
Derivation of $E=pc$ for a massless particle?
20503
Meaning of inner product $\langle \vec{r} | \psi(t)\rangle $
98303
Ward identity derived from global symmetry and SDE, different from that derived from gauge symmetry?
156712
Geometrical or Physical significance (interpretation) of the inner-product $\langle A,B \rangle := Trace (AB^t)$ over $M_n(\mathbb R)$
55905
Find the Hamiltonian given $\dot p$ and $\dot q$
59004
Why does time evolution operator have the form $U(t) = e^{-itH}$?
111191
Show that $P_i$ and $\sum_i P_i$ being idempotent implies $P_i P_j=\delta_{ij}$
21290
Meaning of $\int \phi^\dagger \hat A \psi \:\mathrm dx$