hi,
a further remark: Green function is understood here as the density matrix (equal time Green function). It is not G(p=0, tau) (Green function at zero momentum as a function of imaginary time) for instance which also contains interesting physics.
best regards
Lode Pollet
On May 7, 2012, at 11:27 AM, Matthias Troyer wrote:
Hi,
A new worm code to be released later this year will include the Green's function. However, it might be extremely costly to measure all N^2 values (i->j) if N is large, and thus usually we will either average and measure it only as a function of distance, or from a specific site in most cases.
Best regards
Matthias Troyer
On May 7, 2012, at 11:20 AM, Žiga Osolin wrote:
Hi All,
I have started working on my diploma project, Hubbard model with impurities. It would be really helpful if I could measure green function, but apparently MEASURE[Green Function] = True doesn't work. Looking into source code, I found the measurement code commented with a fix me comment in it. Is this feature still not implemented in ALPS worm, and what does the commented code do (and not do)? Secondly, i found out that this green function (zero output actually, with measurement commented) only generated data for (0 -> i). In inhomogeneous system, i would like all pair (i -> j). Are there any plans for this feature?
Regards, Žiga Osolin