Q1: Consider complex scalar free field given by the following Lagrangian density
1) Find all equations of motion associated with the field. Justify your answer.
2) Assume the following transformation of the field
where ̑̑ is constant, infinitesimal, and real. Prove that the Lagrangian is invariant under the above transformation. (Hint: it is sufficient to show that ̑̑ = 0).
3) Prove that the conserved current j̑(x) associated with this transformation may be written as
4) Prove that the current is conserved (you need to show it obeys the continuity relation ̑̑ = 0).