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CATEGORIES:Discrete Analysis Seminar
SUMMARY:Uniform Spectral Gaps and Paradoxical Decompositio
 ns: the Affine Plane - Lam Pham\, Yale University
DTSTART;TZID=Europe/London:20181121T134500
DTEND;TZID=Europe/London:20181121T144500
UID:TALK114061AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/114061
DESCRIPTION:It is well-known that the non-abelian free group o
 n two generators is paradoxical using 4 pieces. Mo
 re generally\, for a given space X\, an action of 
 this group on X may be paradoxical. In this talk\,
  we will explain how paradoxical decompositions ar
 e directly related to spectral gaps for related un
 itary representations\, and how the number of piec
 es required in the paradoxical decompositions rela
 tes to the actual value of the spectral gap. We wi
 ll present some results on how to find paradoxical
  decompositions of the plane using affine transfor
 mations along with some applications to Kazhdan's 
 Property (T).
LOCATION:MR5\, CMS\, Wilberforce Road\, Cambridge\, CB3 0WB
CONTACT:Aled Walker
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