Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

S - matrix

  1. Nov 4, 2009 #1
    When I have time dependent Hamiltonian


    Is then this relation correct?


    where [tex]\hat{S}(t)[/tex] is S-matrix.

    [tex]\psi_S(t)[/tex] - wave function in Schrodinger picture
  2. jcsd
  3. Nov 4, 2009 #2
    If I want time dependent density matrix is it


    Is this expression OK?

    So I have

    [tex]\left\langle \hat{A} \right\rangle_t=Tr(\hat{A}_S\hat{\rho}_t)=\left\langle \hat{S}^{-1}(t)\hat{A}_H(t)\hat{S}(t) \right\rangle_{\hat{\rho}_H}[/tex]

    Does it make sense?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook