10
$\begingroup$

I'm interested in the (very) low energy limit of quantum electrodynamics. I've seen that taking this limit does not yield Maxwell equations, but a quantum corrected non-linear version of them.

  1. If quantum phenomena are responsible for what we see in the macroscipic world, it is expected that there is a limit which does lead to Maxwell equations from QED? how should I think of this limit?
  2. A classical theory of strong and weak interactions is not physically meaningful. Is this a direct consequence that these fields are (unlike electrodynamics) mediated by short-range interactions? Kindly prove or disprove.
$\endgroup$
  • 5
    $\begingroup$ The quantum corrections are generally only significant for wavelengths comparable to the compton wavelength of the electron, or at intensities where pair-production is significant, if you're talking about the Euler-Heisenberg correction. The low energy limit of QED is Maxwell's equations for ordinary purposes. $\endgroup$ – Ron Maimon Jun 5 '12 at 1:33
2
$\begingroup$
  1. is the classical limit $\hbar\to 0$, not the low energy limit.

  2. is because the mediating fields are massive, so the interaction is very short range.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.