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FIELD
Math:Topology
DATE
Dec 07 (Thu), 2023
TIME
14:00 ~ 15:30
PLACE
1423
SPEAKER
Brendle, Tara
HOST
Kim, Sang-hyun
INSTITUTE
University of Glasgow
TITLE
Semi-direct product structures in mapping class groups of 3-manifolds
ABSTRACT
In-person and Zoom http://kimsh.kr/vz We will show that a certain short exact sequence associated with mapping class groups of 3-manifolds admits a splitting. One by-product of this result is that Out(F_n) arises as a certain stabilizer subgroup of the mapping class group of a connected sum of n copies of S2 x S1. The general case is slightly more complicated: using recent work of Chen-Tshishiku, we will describe the second factor in the semi-direct product structure in terms of the prime decomposition of the 3-manifold. This is joint work with Nathan Broaddus and Andrew Putman.
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