- #1
Silviu
- 624
- 11
Hello! I am reading Peskin's book on QFT and at a point he wants to show that the Dirac field can't be quantified using this commutation relations: ##[\psi_a(x),\psi_b^\dagger(x)]=\delta^3(x-y)\delta_{ab}## (where ##\psi## is the solution to Dirac equation). I am not sure I understand the math behind the commutation relation (I understand why physically it is wrong) as you have a column and a raw vector, so doing the commutation you have the difference between a number and a 4x4 matrix and I am not sure how does this work. Can someone explain it to me? Thank you!