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DTSTART:20260308T070000
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DTSTART:20251102T060000
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DTSTART;TZID=America/Toronto:20260715T153000
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URL:https://uwaterloo.ca/pure-mathematics/events/differential-geometry-work
 ing-seminar-alexander-teeter
SUMMARY:Differential Geometry Working Seminar | Alexander Teeter |\nFreedma
 n’s Results and Donaldson’s Exclusions: Classification of\n4-manifolds
  by intersection forms
CLASS:PUBLIC
DESCRIPTION:ALEXANDER TEETER\, UNIVERSITY OF WATERLOO\n\n_Freedman’s Resu
 lts and Donaldson’s Exclusions: Classification of\n4-manifolds by inters
 ection forms_\n\nWe look at Serre's algebraic classification of symmetric 
 integral\nunimodular forms\, and then Freedman's topological classificatio
 n of\ntopological 4-manifolds by their intersection forms. After\, we take
  a\nturn to looking at Donaldson's exclusions\, finding that smooth\n4-man
 ifolds are not as well behaved. Time permitting\, we will see how\nDonalds
 on's exclusions naturally lead to the existence of exotic\n\\(\\mathbb{R}^
 4\\)s.\n\nMC 5417
DTSTAMP:20260727T234953Z
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