4 papers
Total curvature and spiralling shortest paths
Imre Barany, Krystyna Kuperberg, Tudor Zamfirescu
This paper gives a partial confirmation of a conjecture of P. Agarwal, S. Har-Peled, M. Sharir, and K. Varadarajan that the total curvature of a shortest path on the boundary of a…
A knotted minimal tree
Krystyna Kuperberg
This paper contains a construction of a finite set X in the boundary of the unit 3-ball in R^3 whose minimal tree is knotted. The example answers Problem 5.17 in ''Problems in Low-…
Bihomogeneity and Menger manifolds
Krystyna Kuperberg
For every triple of integers a, b, and c, such that a>O, b>0, and c>1, there is a homogeneous, non-bihomogeneous continuum whose every point has a neighborhood homeomorphic the Car…
Almost-tiling the plane by ellipses
Krystyna Kuperberg, Włodzimierz Kuperberg, Jiří Matoušek +1
For any delta > 1 we construct a periodic and locally finite packing of the plane with ellipses whose delta-enlargement covers the whole plane. This answers a question of Imre Bárá…