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Integral after alpha parametrization

  1. Jan 29, 2014 #1
    I have been stuck on the following double integral for some time:

    ∫(0 to inf) dα1 ∫(0 to inf) dα2 a1^(n1) * exp(-i (α1+α2) m^2) * (α1+α2)^(n2)

    which arose after using alpha paremetrization on a Feynman integral. I was advised by my supervisor to use the substitution α1 = 1/2 (t+u) and α2 = 1/2 (t-u) but after doing this I fail to see how it helps.

    Any advice on how to do this?

  2. jcsd
  3. Jan 29, 2014 #2


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    Staff Emeritus
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    Show your work using the recommended substitutions. Perhaps you made an error in your algebra.
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