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SUMMARY:Virtually unipotent elements of 3-manifold groups - Sami Douba (Mc
 Gill University)
DTSTART:20210507T124500Z
DTEND:20210507T134500Z
UID:TALK158440@talks.cam.ac.uk
CONTACT:76015
DESCRIPTION:Suppose a group G contains an infinite-order element g such th
 at every finite-dimensional linear representation of G maps some nontrivia
 l power of g to a unipotent matrix. As observed by Button\, since unitary 
 matrices are diagonalizable\, and since a unipotent matrix is torsion if i
 ts entries lie in a field of positive characteristic\, such a group G does
  not admit a faithful finite-dimensional unitary representation\, nor is G
  linear over a field of positive characteristic. We discuss manifestations
  of the above phenomenon in various finitely generated groups\, with an em
 phasis on 3-manifold groups
LOCATION:Zoom https://maths-cam-ac-uk.zoom.us/j/95208706709
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