Multiple polylogarithms and Feynman integrals
Christian Bogner (Humbolt Universitat, Berlin)

Polylogarithms and their various generalizations can be seen as functions given by iterated integrals.
The first part of my talk is about a very general class of such iterated integrals, called multiple polylogarithms in several variables, and the possible application of these functions in Feynman integral computations. In the second part I want to discuss a new result for the two-loop sunrise integral with arbitrary masses.
It seems that this is a case where the classes of iterated integrals used in particle physics so far (including the functions of the first part) are not sufficient to express the result.