BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Johnny Nicholson (University College London)
DTSTART:20200714T180000Z
DTEND:20200714T190000Z
DTSTAMP:20260423T004513Z
UID:OSUGGT/2
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/OSUGGT/2/">P
 rojective modules and the homotopy classification of CW-complexes</a>\nby 
 Johnny Nicholson (University College London) as part of Ohio State Topolog
 y and Geometric Group Theory Seminar\n\n\nAbstract\nA basic question in th
 e homotopy classification of CW-complexes is to ask for which finitely pre
 sented groups $G$ does $X \\vee S^2 \\simeq Y \\vee S^2$ imply $X \\simeq 
 Y$\, where $X$ and $Y$ are finite 2-complexes with fundamental group $G$. 
 Despite early interest by Cockroft-Swan and Dyer-Sieradski\, it wasn’t u
 ntil 1976 that examples of non-cancellation were found by Dunwoody and Met
 zler. This led Browning to complete the classification in the finite abeli
 an case. In recent years\, applications to Wall’s D2 problem and the cla
 ssification of manifolds have sparked renewed interest in this problem. In
  this talk\, we will show how the case where $G$ has periodic cohomology c
 an largely be reduced to a question about projective $\\mathbb{Z} G$ modul
 es. We then resolve this by generalising results of Swan from the 1980s.\n
LOCATION:https://researchseminars.org/talk/OSUGGT/2/
END:VEVENT
END:VCALENDAR