Cohomological interpretation of quadratic modular symbols
arXiv:1204.5670
Abstract
Bayer and Blanco-Chacón have recently defined quadratic modular symbols for the Shimura curves X(D,N) attached to Eichler orders of level N of an indefinite quaternion rational algebra of discriminant D. In this paper, we give a cohomological interpretation of these quadratic modular symbols. Explicit computations for the homology of some Shimura curves are also provided.
14 pages and 2 figures. Major revision of the previous draft, including change of title. Comments are welcome