Repository logo
 

Homological stability for automorphism groups

Accepted version
Peer-reviewed

Loading...
Thumbnail Image

Type

Article

Change log

Authors

Randal-Williams, Oscar  ORCID logo  https://orcid.org/0000-0002-7479-2878
Wahl, N 

Abstract

Given a family of groups admitting a braided monoidal structure (satisfying mild assumptions) we construct a family of spaces on which the groups act and whose connectivity yields, via a classical argument of Quillen, homological stability for the family of groups. We show that stability also holds with both polynomial and abelian twisted coefficients, with no further assumptions. This new construction of a family of spaces from a family of groups recovers known spaces in the classical examples of stable families of groups, such as the symmetric groups, general linear groups and mapping class groups. By making systematic the proofs of classical stability results, we show that they all hold with the same type of coefficient systems, obtaining in particular without any further work new stability theorems with twisted coefficients for the symmetric groups, braid groups, automorphisms of free groups, unitary groups, mapping class groups of non-orientable surfaces and mapping class groups of 3-manifolds. Our construction can also be applied to families of groups not considered before in the context of homological stability. As a byproduct of our work, we construct the braided analogue of the category FI of finite sets and injections relevant to the present context, and define polynomiality for functors in the context of pre-braided monoidal categories.

Description

Keywords

Homological stability, Automorphism groups, Mapping class groups, Braid groups, General linear groups, Unitary groups

Journal Title

Advances in Mathematics

Conference Name

Journal ISSN

0001-8708
1090-2082

Volume Title

318

Publisher

Elsevier BV