Some help needed

1. Sep 7, 2005

2. Sep 8, 2005

Neitrino

Sorry but,

Could at least tell me why my question is not getting any replies???
Im very wondered.... its too nonsensical ? If so what do I say wrong?

3. Sep 8, 2005

snooper007

I think the expresion $$<0|\phi(x)\phi(y)|0>$$
survives $$<0|a_p a_q^\dag|0>$$ means:
$$<0|a_p^\dag a_q^\dag|0>$$=0 and $$<0|a_p a_q|0>$$=0;
only $$<0|a_p a_q^\dag|0>$$ 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) $$<0|\phi(x)|$$, 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
4. Sep 8, 2005

Neitrino

(as u posted in homework section)

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

$$<0|\phi(x)=<x|$$ < - ?

and with regard to question 1) I still dont feel comfort with understanding..
seems I did no understand ur reply as it should be

5. Sep 8, 2005

vanesch

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