Mathematics – Algebraic Geometry
Scientific paper
1992-07-23
Mathematics
Algebraic Geometry
31 pages, LaTeX
Scientific paper
In this paper we study the proalgebraic completion of mapping class relative to their maps to the symplectic group. The main result is that the natural map from the unipotent (a.k.a. Malcev) completion of the Torelli group to the prounipotent radical of the Sp_g completion of the mapping class group is a non trivial central extension with kernel isomorphic to Q, at least when g \ge 8. The theorem is proved by relating the central extension to the line bundle associated to the archemidean height of the cycle C - C- in the Jacobian of the curve C. We also develop some of the basic theory of relative completions.
Hain Richard
No associations
LandOfFree
Completions of mapping class groups and the cycle $C - C^-$ does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Completions of mapping class groups and the cycle $C - C^-$, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Completions of mapping class groups and the cycle $C - C^-$ will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-108877