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Srednicki 9.25

  1. Jul 31, 2010 #1
    Can anybody help me out with equation 9.25 in Srednicki's QFT book?

    He says the in the eq. 9.25 an integration by parts has been carried out. I do not see how. I guess we integrate 9.9 and get then 9.25 somehow, but how? Any hints?

    thank you
  2. jcsd
  3. Aug 1, 2010 #2
  4. Aug 4, 2010 #3


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    Yes, starting with 9.9,
    [tex]-{1\over2}\int d^4x(A\partial^\mu\varphi\partial_\mu\varphi+Bm^2\varphi^2)[/tex]
    we partially integrate to move [itex]\partial^\mu[/itex] from the first [itex]\varphi[/itex] to the second, which results in
    [tex]-{1\over2}\int d^4x(-A\varphi\partial^\mu\partial_\mu\varphi+Bm^2\varphi^2)[/tex]
    Then we replace fields by functional derivatives in the way that's done throughout section 9.
  5. Aug 4, 2010 #4
    Thanks so much, Avodyne! You are the Srednicki guy, who never lets us down. I rather randomly pick up the book when I'm in the mood to learn some QFT. Well, and as it is, I always quickly stumble upon some equations I don't understand. So thanks so much for the help, because I really want to learn QFT, no matter what!
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