Recent content by pxb

Hi Reilly, thank you for reply. Of course I tried to consult Google before posting my question, but maybe I didn`t try hard enough... Exactly. As far as I understand the subject, the canonical quantization is defined by insisting on the (anti)commutation relation of the type \{ \psi(x)...

OK, so first of all some unimportant remarks: You are completely right. I somehow forgot that \mathcal{L} is a scalar and then hermitian == real. I also overlooked that \mathcal{L}=i\bar\psi\gamma^\mu\partial_\mu\psi is not hermitian (ie. real). Mea culpa ... If you put t_1=-\infty and...

Hi jostpuur, thanks for interesting responses. Let me comment a bit on them: Only the first one is popular in physics, second is ocassionaly introduced in the textbooks, but not widely used. I don't know why a Lagrangian (and consequently the action) should be real, it only has to be hermitian...

Let's have a theory involving Dirac field \psi. This theory is decribed by some Lagrangian density \mathcal{L}(\psi,\partial_\mu\psi). Taking \psi as the canonical dynamical variable, its conjugate momentum is defined as \pi=\frac{\partial\mathcal{L}}{\partial(\partial_0\psi)} Than the...