- #1

- 32

- 1

[tex]

i \dfrac{dG_{A,B}(t)}{dt} =\delta(t) \left< {[A,B]}\right>+G_{[A,H],B}(t)

[/tex]

the fourier transform is:

[tex]

\omega G_{A,B}(t)=\left< {[A,B]}\right>+G_{[A,H],B}(\omega)

[/tex]

but this would require that the Green's function is 0 for t->inf. Why is that the case? It is clear that it must vanish at t->-inf because of the heaviside function but not at inf.