- yes, an early challenge in learning quantum field theory is learning about the various kinds of propagators and 2-point function, and how the 2-point function is not supported in the lightcone, but rather decays exponentially outside the lightcone. Wikipedia has a discussion of these issues after its list of propagators:
https://en.wikipedia.org/wiki/Propagator#Faster_than_light?
but all of this could stand to be clarified. I've never put enough time into these issues as I should, so I can imagine having fun thinking about it and expanding the Wikipedia article.
[@j_bertolotti](https://mathstodon.xyz/@j_bertolotti ) Greg Egan (npub12cu…d38p)
John Carlos Baez
npub1nf…3nqe4
2025-01-25 18:22:07 UTC
in reply to nevent1q…djt6
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