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I Peskin book on QFT question -- 2 integrals for D(x−y)

  1. Jun 12, 2017 #1
    Hello! Those who used Peskin's book on qft, in chapter 2, Causality (2.4) there are 2 integrals for ##D(x-y)##. Can someone explain to me how does he solve them, as I tried for a bit and didn't manage to do them (actually to get the behavior as ##t \to \infty##). Thank you!
  2. jcsd
  3. Jun 12, 2017 #2


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    IF I've guessed correctly which integrals you mean...

    For the 1st one (leading to asymptotic ##t\to\infty## behaviour), see my final post in this old thread.

    For the 2nd, that's just a matter of passing to polar-momentum coordinates first, and then doing a contour integral. IIRC, there's a more detailed explanation in Rolnick, Appendix D. (If you want more detailed help, you'll probably need to start a thread in the HW forum and show your work.)
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