We show how to color the tiles in a heirarchical tiling system so that the resulting system is not only repetitive (i.e., has the local isomorphism property) but has prescribed col...
We show, with an elementary proof, that the number of halving simplices in a set of n points in R4 in general position is O(n4-2/45). This improves the previous bound of O(n4-1/13...
Any finite set X ⊂ Rd colored with d+3 2 colors, contains a rainbow subset Y ⊂ X, such that any ball that contains Y contains a positive fraction of the points of X. The bound...
Given any knot diagram E, we present a sequence of knot diagrams of the same knot type, for which the minimum number of Reidemeister moves required to pass to E is quadratic with ...
Abstract. We reformulate a known characterization of decomposability of polytopes in a way which may be more computationally convenient, and offer a more transparent proof. We appl...