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DTSTART:20190331T030000
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DTSTAMP:20260403T220447Z
UID:59e3891f8f5af450319984@ist.ac.at
DTSTART:20190306T130000
DTEND:20190306T141500
DESCRIPTION:Speaker: Emo Welzl\nhosted by Uli Wagner\nAbstract: We investig
 ate the connectivity of the flip-graph of all (full ) triangulations of a 
 given finite planar point set P in general position and prove that\, for n
 :=|P| large enough\, both edge- and vertex-connectivity are determined by 
 the minimum degree occurring in the flip-graph\, i.e. the minimum number o
 f flippable edges in any triangulation of P. It is known that every triang
 ulation allows at least (n-4)/2 edge-flips.This result is extended to so-c
 alled subtriangulations\, i.e. the set of all triangulations of subsets of
  P which contain all extreme points of P\, where the flip operation is ext
 ended to bistellar flips (edge-flips\, and insertion and removal of an inn
 er vertex of degree three). Here we prove (n-3)-edge-connectedness (for al
 l P) and (n-3)-vertex-connectedness of n large enough ((n-3) is tight\, si
 nce there is always a subtriangulation which allows exactly $n-3$ bistella
 r flips). This matches the situation known (through the secondary polytope
 ) for so-called regular triangulations.(joint work with Uli Wagner\, IST A
 ustria)
LOCATION:Mondi Seminar Room 3\, Central Building\, ISTA
ORGANIZER:hwagner@ist.ac.at
SUMMARY:Emo Welzl: GeomTop Seminar: Connectivity of the Flip-Graph of Trian
 gulations
URL:https://talks-calendar.ista.ac.at/events/1838
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