A test on analytic continuation of thermal imaginary-time data
Dept. of Physics and Astronomy, SUNY, Stony Brook, NY, 11794, USA
2 Faculty of Physics, University of Bielefeld, 33501, Bielefeld, Germany
* e-mail: email@example.com
Revised: 8 March 2011
Published online: 9 April 2011
Some time ago, Cuniberti et al. have proposed a novel method for analytically continuing thermal imaginary-time correlators to real time, which requires no model input and should be applicable with finite-precision data as well. Given that these assertions go against common wisdom, we report on a naive test of the method with an idealized example. We do encounter two problems, which we spell out in detail; this implies that systematic errors are difficult to quantify. On a more positive note, the method is simple to implement and allows for an empirical recipe by which a reasonable qualitative estimate for some transport coefficient may be obtained, if statistical errors of an ultraviolet-subtracted imaginary-time measurement can be reduced to roughly below the per mille level.
© Springer-Verlag / Società Italiana di Fisica, 2011