On the second homology group of the Torelli subgroup of Aut(Fn)

Autor: Matthew B. Day, Andrew Putman
Rok vydání: 2017
Předmět:
Zdroj: Geometry & Topology. 21:2851-2896
ISSN: 1364-0380
1465-3060
DOI: 10.2140/gt.2017.21.2851
Popis: Let IA_n be the Torelli subgroup of Aut(F_n). We give an explicit finite set of generators for H_2(IA_n) as a GL_n(Z)-module. Corollaries include a version of surjective representation stability for H_2(IA_n), the vanishing of the GL_n(Z)-coinvariants of H_2(IA_n), and the vanishing of the second rational homology group of the level l congruence subgroup of Aut(F_n). Our generating set is derived from a new group presentation for IA_n which is infinite but which has a simple recursive form.
Comment: 39 pages; minor revision; to appear in Geom. Topol
Databáze: OpenAIRE