On the reduction and evaluation of Generalized Polylogarithms up to weight four
Christopher Wever (Karlsruhe University)

The need to perform multi-loop calculations has become commonplace in the LHC era. Experience shows that a large class of multi-loop Feynman integrals are expressible in terms of so-called Generalized (or Goncharov) polylogarithmic functions, which are an extension of the usual classical polylogarithms. It has previously been conjectured that up to weight four, these functions are expressible in terms of the classical (poly-)logarithms Log, Li_2, Li_3, Li_4 and one extra function Li_{2,2}. In this talk I will discuss how one can prove this conjecture. I will also discuss our numerical implementation of the classical (poly-)logarithms and Li_{2,2} in C++.