# Main Page

Welcome to $\Omega$Maxent

$\Omega$Maxent is a highly optimized code for analytic continuation of numerical data obtained in imaginary time or frequency. It is distributed under the GNU General Public License (GPLv3).

It uses the maximum-entropy approach, especially useful whenever the data contains some numerical uncertainties, like in Monte-Carlo based calculations.

This freely available C++ software runs on Linux and Mac platforms. It is both fast and accurate and offers quality-of-fit diagnostic tools. It can handle fermionic and bosonic input Green functions, self-energies, or correlation functions, both in Matsubara frequency or imaginary time, and with arbitrary covariance. All aspects of the implementation critical for accuracy and speed are optimized using specific numerical methods. It uses an approach for choosing the optimal value of the entropy weight $\alpha$ that explicitly maximizes the amount of information extracted from the data.

Users are kindly requested to quote the following paper: Citation

Bug report: Dominic.Bergeron@USherbrooke.ca

# New features in the latest version

• The real part of the retarded function is now also computed. Both real and imaginary parts are saved in file "real_frequency_Green_function.dat". The frequency grid for that function is uniform and can be controlled with parameter "output real frequency grid parameters" in section FREQUENCY GRID PARAMETERS of file "OmegaMaxEnt_input_params.dat".
• You can now also obtain the retarded function during the preprocessing stage using a Padé approximant. See section 2.7 or the user guide for more details.
• The python scripts and data files used to produce the figures are now saved. You can thus display the figures at any time after a program's execution by simply executing the python scripts. See the last paragraph of section 2.9 of the user guide for more details.

See the download page for a full list of features added since the first release.

Developer: Dominic Bergeron, June 2015