Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
the answer is on page 189 of Field Quantization by Greiner & Reinhardt. I reproduce it below for reference (their $\zeta$ is your $\alpha$). (I'll search a bit more for a publicly available source.$\lambda$):
the answer is on page 189 of Field Quantization by Greiner & Reinhardt. I reproduce it below for reference (their $\zeta$ is your $\alpha$). (I'll search a bit more for a publicly available source.)
the answer is on page 189 of Field Quantization by Greiner & Reinhardt. I reproduce it below for reference (their $\zeta$ is your $\alpha$). (I'll search a bit more for a publicly available source.)