Question

Energy interpretation of 1PI effective potential in Weinberg 16.3: is adiabatic turning on the current necessary?

Answer 1

we need the argument of adiabatic turning on? We can simply define E[J] as the ground state energy of the system in the presence of external current J without referring to the case where the external current is zero. Moreover, adiabatic theorem cannot be applied if there is level crossing, which looks the argument of adiabatic turning on is not only unnecessary but also problematic.

Answer 2

HOLA MATE

ANSWER:-

We can  define E[J] as the ground state energy of the system in the presence of external current J without referring to the case where the external current is zero. also, adiabatic theorem cannot be applied if there is level crossing, which looks the argument of adiabatic turning on is not only unnecessary but also problematic.