- #1

Neitrino

- 136

- 0

Would you be so kind to help me with my question please which has been relocated

https://www.physicsforums.com/showthread.php?t=87659

Thanks in advance

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- Thread starter Neitrino
- Start date

- #1

Neitrino

- 136

- 0

Would you be so kind to help me with my question please which has been relocated

https://www.physicsforums.com/showthread.php?t=87659

Thanks in advance

- #2

Neitrino

- 136

- 0

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

snooper007

- 33

- 1

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.

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:

- #4

Neitrino

- 136

- 0

(as u posted in homework section)snooper007 said:[tex] <0|\phi(x)=<x|[/tex] this is a simple calculation

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 don't feel comfort with understanding..

seems I did no understand ur reply as it should be

- #5

vanesch

Staff Emeritus

Science Advisor

Gold Member

- 5,109

- 18

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

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