Tagged Questions
2
votes
0answers
209 views
How does one calculate the quantum propagator for a massless photon
So I want to calculate the quantum massless photon propagator. To do this, I write
$$
A_\mu(x) = \sum\limits_{i=1}^2 \int \frac{d^3p}{(2\pi)^3} \frac{1}{\sqrt{2\omega_p}} \left( \epsilon_\mu^i (p) ...
1
vote
1answer
284 views
Is there orbital angular momentum for all particles?
Light as an electromagnetic wave can be polarized in different ways, e.g. linear or circular. As far as I understand it currently this can be compared to the spin direction of a propagation electron ...
-1
votes
1answer
355 views
The difference between free energy and perpetual motion [closed]
What is the difference between free energy (over unity) and perpetual motion?
Please provide some examples, both real world and theoretical.
6
votes
2answers
716 views
Wheeler-Feynman theory, QED without fields, vacuum polarization
Initially Wheeler and Feynman postulated that, the electromagnetic field is just a set of bookkeeping variables required in a Hamiltonian description. This is very neat because makes the point of ...
