Eisenstein cocycles in motivic cohomology

Abstract: I will describe joint work with Akshay Venkatesh on the construction and study of GL_2(Z)-cocycles valued in second K-groups of the function fields of squares of the multiplicative group over the rationals and of a universal elliptic curve over a modular curve. I will also describe the pullbacks of their restrictions to congruence subgroups under torsion sections, relating these specializations to explicit maps on homology groups of modular curves

Mathematics

Audience: researchers in the topic

CRM workshop: Arithmetic quotients of locally symmetric spaces and their cohomology

Series comments: Zoom registration: umontreal.zoom.us/meeting/register/tJwkfu6vpzItHtPb49yDLrPlCtLyb5kvjuYP