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SUMMARY:Dehn twists and free subgroups of the symplectic mapping class gro
 up - Ailsa Keating\, MIT
DTSTART:20130116T160000Z
DTEND:20130116T170000Z
UID:TALK40440@talks.cam.ac.uk
CONTACT:Ivan Smith
DESCRIPTION:Given two Lagrangian spheres in an exact symplectic manifold\,
  we present\nconditions under which the Dehn twists about them generate a 
 free\nnon-abelian subgroup of the symplectic mapping class group. This ext
 ends a\nresult of Ishida for Riemann surfaces. The proof generalises the\n
 categorical version of Seidel's long exact sequence to arbitrary powers of
 \na fixed Dehn twist. Time allowing\, we construct families of examples\nc
 ontaining such spheres.\n
LOCATION:MR13
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