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TZID:Europe/Vienna
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DTSTART:20260329T030000
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DTSTAMP:20260415T072605Z
UID:6847fefd4a140502881795@ist.ac.at
DTSTART:20260401T153000
DTEND:20260401T163000
DESCRIPTION:Speaker: Marc Lackenby\nhosted by Laszlo Erdös & Uli Wagner\nA
 bstract: In his final paper in 1954\, Alan Turing wrote No systematic meth
 od is yet known by which one can tell whether two knots are the same.' Wit
 hin the next 20 years\, Wolfgang Haken and Geoffrey Hemion had discovered 
 such a method. However\, the computational complexity of this problem rema
 ins unknown. In my talk\, I will give a survey on this area\, that draws o
 n the work of many low-dimensional topologists and geometers. Unfortunatel
 y\, the current upper bounds on the computational complexity of the knot e
 quivalence problem remain quite poor. However\, there are some recent resu
 lts indicating that\, perhaps\, knots are more tractable than they first s
 eem. Specifically\, I will explain a theorem that provides\, for each knot
  type K\, a polynomial p_K with the property that any two diagrams of K wi
 th n_1 and n_2 crossings differ by at most p_K(n_1) + p_K(n_2) Reidemeiste
 r moves.
LOCATION:Raiffeisen Lecture Hall\, Central Building\, ISTA
ORGANIZER:boosthui@ist.ac.at
SUMMARY:Marc Lackenby: The complexity of knots
URL:https://talks-calendar.ista.ac.at/events/6328
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