• Invariants of Closed Braids via Counting Surfaces 

      [OWP-2012-15] Brandenbursky, Michael (Mathematisches Forschungsinstitut Oberwolfach, 2012)
      A Gauss diagram is a simple, combinatorial way to present a link. It is known that any Vassiliev invariant may be obtained from a Gauss diagram formula that involves counting subdiagrams of certain combinatorial types. In ...
    • On the autonomous metric on the group of area-preserving diffeomorphisms of the 2-disc 

      [OWP-2012-16] Brandenbursky, Michael; Kȩdra, Jarek (Mathematisches Forschungsinstitut Oberwolfach, 2012)
      Let D2 be the open unit disc in the Euclidean plane and let G:=Diff(D2;area) be the group of smooth compactly supported area-preserving diffeomorphisms of D2. For every natural number k we construct an injective ...