Stability in the homology of congruence subgroups
成果类型：
Article
署名作者：
Putman, Andrew
署名单位：
Rice University
刊物名称：
INVENTIONES MATHEMATICAE
ISSN/ISSBN：
0020-9910
DOI：
10.1007/s00222-015-0581-0
发表日期：
2015
页码：
987-1027
关键词：
摘要：
The homology groups of many natural sequences of groups {G(n)}(n=1)(infinity) (e.g. general linear groups, mapping class groups, etc.) stabilize as n -> infinity. Indeed, there is a well-known machine for proving such results that goes back to early work of Quillen. Church and Farb discovered that many sequences of groups whose homology groups do not stabilize in the classical sense actually stabilize in some sense as representations. They called this phenomena representation stability. We prove that the homology groups of congruence subgroups of GL(n) (R) (for almost any reasonable ring R) satisfy a strong version of representation stability that we call central stability. The definition of central stability is very different from Church-Farb's definition of representation stability (it is defined via a universal property), but we prove that it implies representation stability. Our main tool is a new machine for proving central stability that is analogous to the classical homological stability machine.