- #1
Kalimaa23
- 279
- 0
Greetings,
I stumbled across two question that I have no idea on how to answer them.
1) The interaction term in a scalar field theory is [tex]-\frac{\lambda}{4!} \phi^4[/tex]
Why should lambda be positive? (they say look at the energy of the ground state...)
2) Write down the Feynman rules for phi^4
I have no clue as to how you get the two intersecting lines that give is -i lambda vertex. I see where the propagator comes from though.
Any thougths?
I stumbled across two question that I have no idea on how to answer them.
1) The interaction term in a scalar field theory is [tex]-\frac{\lambda}{4!} \phi^4[/tex]
Why should lambda be positive? (they say look at the energy of the ground state...)
2) Write down the Feynman rules for phi^4
I have no clue as to how you get the two intersecting lines that give is -i lambda vertex. I see where the propagator comes from though.
Any thougths?