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SUMMARY:Common finite covers and quasitrees [MPIM]
DTSTART:20260129T153000Z
DTEND:20260129T170000Z
DTSTAMP:20260420T151000Z
UID:indico-event-1077@math-events.uni-bonn.de
DESCRIPTION:Speakers: Martin Bridson (University of Oxford)\n\nOberseminar
  Differentialgeometrie\nSam Shepherd and I proved that if two finite sim
 plicial complexes have isomorphic universal covers and free fundamental gr
 oups\, then they have a common finite cover. In the 1-dimensional case (gr
 aphs)\, this is Leighton's Theorem. I shall discuss various extensions of
  Leighton's Theorem and examples that illustrate its limitations\, with
  a focus on coverings by quasitrees. I shall then outline a proof of our t
 heorem\, which involves the construction of auxiliary CAT(0) cube complexe
 s.\n\nhttps://math-events.uni-bonn.de/event/1077/
LOCATION:MPIM\, Vivatsgasse\,  7 - Lecture Hall (Max Planck Institute for 
 Mathematics)
URL:https://math-events.uni-bonn.de/event/1077/
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