1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Chapter 6 of Srednicki's problems.

  1. Jul 9, 2014 #1


    User Avatar
    Gold Member

    1. The problem statement, all variables and given/known data
    I am reading the solutions manual of Srednicki's textbook in QFT (alongside reading the textbook itself).
    Here it is:

    So the equation that he arrives at (6.27).

    I am not sure I understand how did he arrive at the RHS?

    I mean if I write the exponent down, i.e [tex] e^{-(q_2-q_1)^2/(2c)} e^{-(q_1-q_0)^2/(2c)}[/tex]
    then I get:
    [tex]-[(q_2-q_1)^2/2c + (q_1 -q_0)^2/2c] = -[\frac{(q_2-q_0)^2}{4c} +\frac{2q_1^2-2q_1(q_2+q_0)+q_2q_0}{2c}[/tex]

    Now to get the RHS we need to assume that: [tex]q_2q_0 - 2q_1(q_2+q_0)=0[/tex] which I don't see it written in the textbook, perhaps I skipped over it...

    Is it written in the book?

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Jul 9, 2014 #2
    I got the answer in (6.27) without any extra assumptions.

    Do your Gaussian integral more carefully! :cool:
  4. Jul 10, 2014 #3


    User Avatar
    Gold Member

    OK, I can see my mistake, it shouild be:

    [tex] -[(q_2-q_1)^2/2x +(q_1-q_0)^2/2c] = -(q_2-q_0)^2/4c - (q_1 - (q_0+q_2)/2)^2/c [/tex]

    So all is OK.
    :-D foolish me.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Threads - Chapter Srednicki's problems Date
MTW Chapter 21 Arcane Language Nov 10, 2017
Tsampirlis Chapter 1 Inner Product Feb 16, 2016
Griffith's ED Chapter 4 Clarification (Bound Charges) Apr 19, 2015
Sean Carroll Chapter 5.1 Feb 8, 2015
Srednicki QFT chapter 67, LSZ formula Jun 8, 2012