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We state an open problem in the theory of diversities: what is the worst case minimal distortion embedding of a diversity on $n$ points in $ell_1$. This problem is the diversity analogue of a famous problem in metric geometry: what is the worst case minimal distortion embedding of an $n$-point metric space in $ell_1$. We explain the problem, state some special classes of diversities for which the answer is known, and show why the standard techniques from the metric space case do not work. We then outline some possible lines of attack for the problem that are not yet fully explored.
Diversities are a generalization of metric spaces, where instead of the non-negative function being defined on pairs of points, it is defined on arbitrary finite sets of points. Diversities have a well-developed theory. This includes the concept of a
Diversities are a generalization of metric spaces in which a non-negative value is assigned to all finite subsets of a set, rather than just to pairs of points. Here we provide an analogue of the theory of negative type metrics for diversities. We in
Let $Dgeq 2$, $Ssubset mathbb R^D$ be finite and let $phi:Sto mathbb R^D$ with $phi$ a small distortion on $S$. We solve the Whitney extension-interpolation-alignment problem of how to understand when $phi$ can be extended to a function $Phi:mathbb R
A quasiconformal tree is a doubling metric tree in which the diameter of each arc is bounded above by a fixed multiple of the distance between its endpoints. In this paper we show that every quasiconformal tree bi-Lipschitz embeds in some Euclidean s
The approximation of a circle with a fine square grid distorts the perimeter by a factor of $tfrac{4}{pi}$. We prove that this factor is the same on average for approximations of any curve with any Delaunay mosaic (known as Voronoi path), and extend