Flow equations for Hamiltonians
Seminar Room 1, Newton Institute
This is a method to diagonalize or block-diagonalize a Hamiltonian by a
continuous unitary transformation.
After an introduction into the method a short survey of applications are
As an example the elimination of the electron-phonon interaction in
second order in the coupling is performed.
Then a gradient-procedure which minimizes a cost-function is shown.
A procedure to bring the Hubbard Hamiltonian to molecular-field form is
given as a second example.
FW, Annalen der Physik (Leipzig) 3 (1994) 77