Abstract
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.
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Burnier, Y., Laine, M. & Mether, L. A test on analytic continuation of thermal imaginary-time data. Eur. Phys. J. C 71, 1619 (2011). https://doi.org/10.1140/epjc/s10052-011-1619-0
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DOI: https://doi.org/10.1140/epjc/s10052-011-1619-0