[QUE/QFT-05002] QFT-PROBLEM

Starting from the Lagrangian for a complex scalar field obtain the Hamiltonian for a free complex Klein Gordon field. and show that quantized field obeys \begin{equation}\label{eq01} \big[H, \pi(x)\big] = - i \big( \nabla^2- \mu^2\big) \phi^*(x) . \end{equation}