Progress on Complex Langevin simulations of a finite density matrix model for QCD
Institute for Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany
2 Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, United Kingdom
3 Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794
4 Thomas Jefferson National Accelerator Facility, Newport News, VA 23606, USA
5 Department of Physics, College of William and Mary, Williamsburg, VA 23187-8795, USA
6 Institute for Theoretical Physics, Universität Heidelberg, Philosophenweg 12, D-69120 Germany
* Speaker, e-mail: email@example.com
Published online: 26 March 2018
We study the Stephanov model, which is an RMT model for QCD at finite density, using the Complex Langevin algorithm. Naive implementation of the algorithm shows convergence towards the phase quenched or quenched theory rather than to intended theory with dynamical quarks. A detailed analysis of this issue and a potential resolution of the failure of this algorithm are discussed. We study the effect of gauge cooling on the Dirac eigenvalue distribution and time evolution of the norm for various cooling norms, which were specifically designed to remove the pathologies of the complex Langevin evolution. The cooling is further supplemented with a shifted representation for the random matrices. Unfortunately, none of these modifications generate a substantial improvement on the complex Langevin evolution and the final results still do not agree with the analytical predictions.
© The Authors, published by EDP Sciences, 2018
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