- #1
Breo
- 177
- 0
Hello,
Can someone tell me how to derive:
$$ grad\hat{\phi} $$
from:
$$ \hat{P}= -:\int \mathrm{d³}x [\pi (x) grad\hat{\phi}(x)]: = \int \mathrm{d³}p [p a⁺(p)a(p)] $$
Are all vectors. Note normal ordering ":" is used.
I want to understand well QFT and want to learn to do this calcs.
Thank you in before hand.
Can someone tell me how to derive:
$$ grad\hat{\phi} $$
from:
$$ \hat{P}= -:\int \mathrm{d³}x [\pi (x) grad\hat{\phi}(x)]: = \int \mathrm{d³}p [p a⁺(p)a(p)] $$
Are all vectors. Note normal ordering ":" is used.
I want to understand well QFT and want to learn to do this calcs.
Thank you in before hand.