English

Point pushing, homology, and the hyperelliptic involution

Geometric Topology 2011-10-10 v1 Algebraic Geometry

Abstract

The hyperelliptic Torelli group is the subgroup of the mapping class group consisting of elements that act trivially on the homology of the surface and that also commute with some fixed hyperelliptic involution. We prove a Birman exact sequence for hyperelliptic Torelli groups, and we show that this sequence splits. As a consequence, we show that the hyperelliptic Torelli group is generated by Dehn twists if and only if it is generated by reducible elements. We also give an application to the kernel of the Burau representation.

Keywords

Cite

@article{arxiv.1110.1397,
  title  = {Point pushing, homology, and the hyperelliptic involution},
  author = {Tara E. Brendle and Dan Margalit},
  journal= {arXiv preprint arXiv:1110.1397},
  year   = {2011}
}

Comments

26 pages, 4 figures

R2 v1 2026-06-21T19:16:23.588Z