We present a compact analytic formula for the two-loop six-particle MHV
remainder function (equivalently, the two-loop light-like hexagon Wilson loop)
in N = 4 supersymmetric Yang-Mills theory in terms of the classical
polylogarithm functions Li_k with cross-ratios of momentum twistor invariants
as their arguments. In deriving our result we rely on results from the theory
of motives.Comment: 11 pages, v2: journal version, minor corrections and simplifications,
additional details available at http://goo.gl/Cl0