Multiple period integrals and cohomology
arXiv:1512.06225 · doi:10.2140/ant.2016.10.645
Abstract
This work gives a version of the Eichler-Shimura isomorphism with a non-abelian in group cohomology. Manin has given a map from vectors of cusp forms to a noncommutative cohomology set by means of iterated integrals. We show Manin's map is injective but far from surjective. By extending Manin's map we are able to construct a bijective map and remarkably this establishes the existence of a non-abelian version of the Eichler-Shimura map.