All Questions
4
questions
1
vote
1
answer
429
views
What exactly does it mean by gauge-invariant "operators"?
For simplicity, let us consider $U(1)$ gauge theory without matter fields.
At classical level, the gauge field $A^\mu$ has the gauge transformation law
\begin{equation}
A^\mu \to A^\mu +\partial^\mu \...
- 1,669
4
votes
1
answer
310
views
Local gauge transformation in Fock space of photons
I'm currently playing around with gauge transformations in the Fock space of photons.
Let's consider a local gauge transformation with gauge function $f(\mathbf{r})$.
So the magnetic vector potential ...
- 40.1k
3
votes
2
answers
483
views
Is electric field operator in Schrödinger picture time-dependent?
We know that in the Schrödinger picture, operators are time-independent if they do not have explicit time-dependence.
So do electric field and vector potential field operators have time dependence in ...
- 1,369
2
votes
1
answer
440
views
Electron photon interaction - commutation of $\mathbf{A}$ and $\mathbf{p}$
I'm trying to figure out the radiative transition rates between electronic levels due to EM radiation using FGR as done by Merzbacher, this online source, and others.
I have two questions regarding ...
- 695