Notes on hyperelliptic mapping class groups

Boggi, Marco 

Glasgow mathematical journal, Tome 66 (2024) no. 1, pp. 126-161

Résumé

Hyperelliptic mapping class groups are defined either as the centralizers of hyperelliptic involutions inside mapping class groups of oriented surfaces of finite type or as the inverse images of these centralizers by the natural epimorphisms between mapping class groups of surfaces with marked points. We study these groups in a systematic way. An application of this theory is a counterexample to the genus $2$ case of a conjecture by Putman and Wieland on virtual linear representations of mapping class groups. In the last section, we study profinite completions of hyperelliptic mapping class groups: we extend the congruence subgroup property to the general class of hyperelliptic mapping class groups introduced above and then determine the centralizers of multitwists and of open subgroups in their profinite completions.

Détail

DOI : 10.1017/S0017089523000381

Mots-clés : Hyperelliptic mapping class groups, topological surfaces, moduli of curves, virtual linear representations of mapping class groups, profinite hyperelliptic mapping class groups