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SUMMARY:Subgroups of hyperbolic groups\, finiteness properties and complex
  hyperbolic lattices - Pierre Py (Université de Strasbourg)
DTSTART:20230310T134500Z
DTEND:20230310T144500Z
UID:TALK194431@talks.cam.ac.uk
CONTACT:76015
DESCRIPTION:Following C.T.C. Wall\, we say that a group G is of type F_n i
 f it admits a classifying space which is a CW-complex with finite n-skelet
 on. For n=2 one recovers the notion of being finitely presented. We prove 
 that in a cocompact arithmetic lattice in the group PU(m\,1) with positive
  first Betti number\, deep enough finite index subgroups admit plenty of h
 omomorphisms to Z with kernel of type F_{m-1} but not of type F_m. This pr
 ovides many non-hyperbolic finitely presented subgroups of hyperbolic grou
 ps and answers an old question of Brady. This is based on a joint work wit
 h C. Llosa Isenrich. \n
LOCATION:MR13
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