All Questions
2 questions
2
votes
1
answer
877
views
Hermitian conjugate of 4-derivative $\partial_\mu$
I want to find the hermitian conjugate of 4-derivative $\partial_\mu$ for the real scalar Lagrangian defined as
$$\mathcal{L} = \frac{1}{2} (\partial_\mu \phi)^\dagger(\partial^\mu\phi) - \frac{1}{2}...
3
votes
1
answer
165
views
Schwartz QFT coupling to the photon
I am reading Schwartz's QFT textbook. In Eq. (10.104) he writes:
$$
\left[i\partial_\mu-eA_\mu,i\partial_\nu-eA_\nu\right]~=~-e i[\partial_\mu A_{\nu}-\partial_\nu A_{\mu}]~=~
-e i F_{\mu \nu}. \tag{...