Renormalizations of multiple zeta values


Jianqiang Zhao

13:30:00 - 14:30:00

103 , Mathematics Research Center Building (ori. New Math. Bldg.)

Calculating multiple zeta values at arguments of mixed signs in a way that is compatible with both the quasi-shuffle product and the meromorphic continuation, is commonly referred to as the renormalization problem for multiple zeta values. In this talk, we consider the set of all solutions to this problem and provide a framework for comparing its elements in terms of a free and transitive action of a particular subgroup of the group of characters of the quasi-shuffle Hopf algebra. This provides a transparent way of relating different solutions at non-positive values, which answers an open question in the recent literature. This is a joint work with Ebrahimi-Fard, Manchon and Singer.