Dimension reduction techniques for $\ell_p$, $1 \le p \le 2$, with applications

TL;DR

This paper extends dimension reduction techniques to all $\, ext{l}_p$ spaces between 1 and 2, providing new embeddings with bounded fidelity range and improved bounds for proximity problems.

Contribution

It generalizes the Ostrovsky-Rabani approach from $\, ext{l}_1$ to all $\, ext{l}_p$ spaces for $1 \,\leq\, p \,\leq \, 2$, with enhanced bounds and applications.

Findings

Developed bounded range embeddings for all $\, ext{l}_p$ spaces with $1 \,\leq\, p \,\leq \, 2$

Achieved improved bounds related to intrinsic dimensionality

Enhanced results for clustering and proximity problems

Abstract

For Euclidean space ($\ell_2$), there exists the powerful dimension reduction transform of Johnson and Lindenstrauss, with a host of known applications. Here, we consider the problem of dimension reduction for all $\ell_p$ spaces $1 \le p \le 2$. Although strong lower bounds are known for dimension reduction in $\ell_1$, Ostrovsky and Rabani successfully circumvented these by presenting an $\ell_1$ embedding that maintains fidelity in only a bounded distance range, with applications to clustering and nearest neighbor search. However, their embedding techniques are specific to $\ell_1$ and do not naturally extend to other norms. In this paper, we apply a range of advanced techniques and produce bounded range dimension reduction embeddings for all of $1 \le p \le 2$, thereby demonstrating that the approach initiated by Ostrovsky and Rabani for $\ell_1$ can be extended to a much more general framework. We also obtain improved bounds in terms of the intrinsic dimensionality. As a result we achieve improved bounds for proximity problems including snowflake embeddings and clustering.