On the impossibility of dimension reduction for doubling subsets of lP

A major open problem in the field of metric embedding is the existence of dimension reduction for n-point subsets of Euclidean space, such that both distortion and dimension depend only on the doubling constant of the point set, and not on its cardinality. In this paper, we negate this possibility for lp spaces with p 2. In particular, we introduce an n-point subset of lp with doubling constant O(1), and demonstrate that any embedding of the set into dp with distortion D must have D ≥ (( log n d ) 1 2 â'1p ).