Gupta/Bleuler Quantization Method
Results of quantization method:
- Four modes of transmission:
- Two transverse waves.
- One longitudinal wave.
- One scalar wave.
Transverse waves are photons for EM.
The supplementary condition is imposed to eliminate scalar and longitudinal
modes for photons as real particles. There can be no scalar or longitudinal
modes for a spin 1 4D wave field.