many thanks for help. I find a commutator value depending upon the system energy :
commutator = E(m) U(m,n) if E= E(m) and - E(n) U(m,n) if E=E(n).
in other cases it's zero.
Is this correct ?
Homework Statement
|phi (n)> being eigen states of hermitian operator H ( H could be for example the hamiltonian
of anyone physical system ). The states |phi (n)> form an orthonormal discrete basis.
The operator U(m,n) is defined by:
U(m,n)= |phi(m)><phi(n)|
Calculate the commutator...