Hi tasfaye mamuye,

Maxent is very tricky to use, it is easy to get consistent but wrong spectra. We do not have a tutorial for it available. However, we do have a parameter file as part of hybdoc.pdf. Please have a look at Fig. 1 and try to adapt this parameter file to your data.

I suggest that you start with a few trial functions that you know on the real axis (e.g. a Gaussian, a double Gaussian, etc) and continue these to the imaginary axis, then add some noise, and then use maxent to continue it back to the real axis. This will give you a feeling for how maxent behaves and where it is reliable.

If you’re interested in the method itself then have a look here: M. Jarrell and J. E. Gubernatis, Physics Reports, 269, 133 (1996), ISSN 0370-1573.

Regarding plotting the phase diagram: Are you interested in the Mott transition in the single site DMFT for the Hubbard model? If you’re just interested in checking if a system is metallic or insulating you can use indicators on the imaginary axis, e.g. \beta G(\beta/2), which gives you an approximation to the density of states at the Fermi energy. That’s easier and more reliable than maxent.

Best, Emanuel

On Jan 15, 2014, at 2:01 AM, tesfaye mamuye tesfa2127@yahoo.com wrote:

Dear developers

I'm interest on DMFT code in ALPS. I need to do analytic continuation of the CT-QMC data to real frequency. I want to use the ALPS MaxEnt code. But there is no elaborate documentation regarding MaxEnt. In .bybdoc.pdf' documentation it is pointed out that a tutorial for alps MaxEnt code will be provided elsewhere.

1. Ca someone send me the code or describe parameters, input/output files and any necessary information to run MaxEnt ? or any one who will guide me on MaxEnt?

2. How to plot the phase diagram (T Vs U) for the DMFT impurity silver