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Homework Help: Some help needed

  1. Sep 7, 2005 #1
  2. jcsd
  3. Sep 8, 2005 #2
    Sorry but,

    Could at least tell me why my question is not getting any replies???
    Im very wondered.... its too nonsensical :confused: ? If so what do I say wrong?
  4. Sep 8, 2005 #3
    I think the expresion [tex] <0|\phi(x)\phi(y)|0> [/tex]
    survives [tex] <0|a_p a_q^\dag|0> [/tex] means:
    [tex] <0|a_p^\dag a_q^\dag|0> [/tex]=0 and [tex] <0|a_p a_q|0> [/tex]=0;
    only [tex] <0|a_p a_q^\dag|0> [/tex] survives, of course p and q are arbitary,
    not single p and single q. the final result will be an integral over all possible p or q.

    (2) [tex] <0|\phi(x)|[/tex], is just complex conjugate of (2.41).
    there is no special physical significance here, the author, I guess, just mentioned NR
    case to make the formula be easily understood.
    Last edited: Sep 8, 2005
  5. Sep 8, 2005 #4
    (as u posted in homework section)

    Dear Snooper007 thks for ur reply..
    [tex] <0|\phi(x)[/tex] it is a complex conjugation of [tex] \phi(x)|0>[/tex]
    So [tex] <0|\phi(x)=\int{\frac{d^3 p}{(2\pi)^3}\frac{1}{2E_p}e^{ipx}<p|[/tex]

    [tex] <0|\phi(x)=<x|[/tex] < - ?

    and with regard to question 1) I still dont feel comfort with understanding..
    seems I did no understand ur reply as it should be
  6. Sep 8, 2005 #5


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    I wonder in what colleges one studies Peskin and Schroeder...
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