- #1
praharmitra
- 311
- 1
Can someone explain to me how the authors got the second equation of eq (4.19), Page 84, of Peskin Schroeder.
The equation is:
[tex]
H_I(t) = e^{iH_0(t-t_0)}(H_{\text{int}}) e^{-iH_0(t-t_0)} = \int d^3x \frac{\lambda}{4!} \phi_I(t,\textbf{x})^4
[/tex]
where
[tex]
H_{\text{int}} = \int d^3x \frac{\lambda}{4!} \phi^4(\textbf{x})
[/tex]
I do not understand how the second part of this eq is equal to the third. Please explain.
The equation is:
[tex]
H_I(t) = e^{iH_0(t-t_0)}(H_{\text{int}}) e^{-iH_0(t-t_0)} = \int d^3x \frac{\lambda}{4!} \phi_I(t,\textbf{x})^4
[/tex]
where
[tex]
H_{\text{int}} = \int d^3x \frac{\lambda}{4!} \phi^4(\textbf{x})
[/tex]
I do not understand how the second part of this eq is equal to the third. Please explain.