- #1

HomogenousCow

- 737

- 213

2. How can the scalar fields suddenly be opeartors? I never understood this step mathematically, one moment they are working with the fields in a scalar differential equation, and the next they are somehow opeartors which obey a non-zero commutation relation (something a simple multiplicative scalar operator could not obey)

3. How are particles in QFT defined? Particles in QM and SR were defined by localized lumps of four-momentum traveling through spacetime. How do we even define localization in QFT without a position (or maybe a four-position) operator?