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DTSTART:20240310T070000
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DTSTART:20231105T060000
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DTSTART;TZID=America/Toronto:20241004T153000
SEQUENCE:0
TRANSP:TRANSPARENT
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URL:https://uwaterloo.ca/pure-mathematics/events/geometry-and-topology-semi
 nar-20
SUMMARY:Geometry and Topology Seminar
CLASS:PUBLIC
DESCRIPTION:NIKOLAY BOGACHEV\, UNIVERSITY OF TORONTO\n\nCommensurability cl
 asses and quasi-arithmeticity of hyperbolic\nreflection groups\n\nIn the f
 irst part of the talk I will give an intro to the theory of\nhyperbolic re
 flection groups initiated by Vinberg in 1967. Namely\, we\nwill discuss th
 e old remarkable and fundamental theorems and open\nproblems from that tim
 e. The second part will be devoted to recent\nresults regarding commensura
 bility classes of finite-covolume\nreflection groups in the hyperbolic spa
 ce H^n. We will also discuss\nthe notion of quasi-arithmeticity (introduce
 d by Vinberg in 1967) of\nhyperbolic lattices\, which has recently become 
 a subject of active\nresearch. The talk is partially based on a joint pape
 r with S. Douba\nand J. Raimbault.\n\nMC 5417
DTSTAMP:20260504T235103Z
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