Mixed sheaves on Shimura varieties and their higher direct images in toroidal compactifications
Algebraic Geometry
2017-06-23 v2
Abstract
Let (P,X) be Shimura data, M=M(P,X,K) the Shimura variety of level K. To an algebraic representation of P, one can associate a mixed sheaf (variation of Hodge structure, l-adic sheaf) on M. In the paper, we study the degeneration of such sheaves along strata in toroidal compactifications of M. The main result (2.8 in the Hodge setting, 3.9 in the l-adic setting) gives a formula for this degeneration in terms of Hochschild cohomology of certain unipotent subgroups of P. The new version differs from the earlier one in that the proof of 2.8 was rewritten. In particular, the effect of Saito's specialization functor along a stratum is identified on variations obtained via representations.
Keywords
Cite
@article{arxiv.math/9811018,
title = {Mixed sheaves on Shimura varieties and their higher direct images in toroidal compactifications},
author = {J. Wildeshaus},
journal= {arXiv preprint arXiv:math/9811018},
year = {2017}
}
Comments
32 pages, no figures. To appear in J. of Alg. Geom