Even Galois representations and the cohomology of GL(2,Z)
arXiv:1702.07417
Abstract
Let be a two-dimensional even Galois representation which is induced from a character of odd order of the absolute Galois group of a real quadratic field. After imposing some additional conditions on , we attach to a Hecke eigenclass in the cohomology of with coefficients in a certain infinite-dimensional vector space over a field of characteristic not equal to 2.