Addendum to: commensurations of the Johnson kernel

Brendle, T. and Margalit, D. (2008) Addendum to: commensurations of the Johnson kernel. Geometry and Topology, 12, pp. 97-101. (doi: 10.2140/gt.2008.12.97)

Abstract

Let K(S) be the subgroup of the extended mapping class group, Mod(S), generated by Dehn twists about separating curves. In our earlier paper, we showed that Comm(K(S))≅Aut(K(S))≅Mod(S) when S is a closed, connected, orientable surface of genus g ≥ 4. By modifying our original proof, we show that the same result holds for g ≥ 3, thus confirming Farb’s conjecture in all cases (the statement is not true for g ≤ 2).

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Brendle, Professor Tara
• Authors: Brendle, T., and Margalit, D.
• Subjects: Q Science > QA Mathematics
• College/School: College of Science and Engineering > School of Mathematics and Statistics > Mathematics
• Journal Name: Geometry and Topology
• ISSN: 1465-3060
• ISSN (Online): 1364-0380