Hi everyone,(adsbygoogle = window.adsbygoogle || []).push({});

I have a question that, when came to me, sounded a bit silly to me as well, but then I realized, I myself maybe don't understand the logic behind this 100%, so why not discussing with you about it.

So my question is the following. Usually we are used to do quantum field theory starting from a classical lagrangian with classical fields (say electromagnetism), and then do our usual quantization proceedure, one way or another and get say qed.

Now when we look at electromagnetism, we can also study the classical field theory, and this already provides us with a lot of interesting information, for example the existence of electromagnetic waves. Similarly with gravity, that we still cannot quantize, we study the classical field theory and we get a lot of information on the dynamics including the existence of gravitational waves.

Now my silly question is, can we extract anything reasonable from qcd as a classical field theory? Or say yang mills in general. For example, would we find gluonic waves?

Clearly I understand very well that the difference between qcd and qed ist that we see phenomena of qcd only on very small scales (due to confinement) and somehow the theory and the phenomena we want to understand are naturally quantum phenomena. Moreover something like asymptotic freedom I guess makes sense only at the quantum level. Still, I was wondering if we can really exclude a priori that anything interesting can be extracted from classical qcd ( I should probably call it just cd, instead of qcd). Or said in other terms, suppose I didn't know about color confinement, asymptotic freedom and so on, and I just wanted to investigate classical yang mills theory for a given group SU(N). Would I be able to see some interesting physics compared to what I know from em and gravity, already at the classical level?

Sleuth

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# A QCD as a classical field theory?

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