ABSTRACT
In this chapter, we want to construct, starting from the Feynman method, some general properties of quantum mechanics (QM) and of field theory. In particular:
Equations of motion in operator form
Canonical commutation rules in QM: [ q i , p k ] = i ℏ δ i k $ [q_{i},p_{k}]=i \hslash \delta _{ik} $ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315369723/48d43afe-85b0-4e2b-a932-df2bd1af07be/content/inline-math4_295.tif"/>
Symmetries and conserved quantities – Noether’s theorem
The Ward identity
