A Dedekind-Rademacher cocycle for Bianchi groups

Abstract

We construct a generalization of the Dedekind-Rademacher cocycle to congruence subgroups of ${\mathrm{SL}}_2(\mathbb{C})$, and derive some of its basic properties. In particular, we show that it parametrizes a family of $L$-values and prove the integrality of these values.

14 pages