Dimension Thresholds for Relative-Error Representations of Finite Metrics in Pseudo-Euclidean Spaces
Abstract
A finite metric space with N points admits an exact representation in a pseudo-Euclidean space of dimension at most N−1. We study the minimum dimension required for relative-error approximation of squared distances. Our main result gives an upper bound for arbitrary metrics in terms of local distance ratios: for 4/5<ε<1, dimension O((N/k)log N+kρk4log N/(ε−4/5)2) suffices, where ρk is the largest ratio, over all points, between the distance to the kth closest point (counting the point itself) and the nearest-neighbour distance. The proof combines a low-rank landmark approximation with a sparse correction controlled by its factorization norm. For metrics with distances in [1,Φ], where Φ≥5 is fixed, the worst-case dimension is Θ(N) for 0<ε<4/5, lies between Ω(√N) and O(√Nlog N) for 4/5<ε<12/13, and is Θ(log N) for ε>(Φ2−1)/(Φ2+1). For Φ>5, an intermediate range remains without matching bounds. Sign-pattern counting yields the Ω(√N) lower bound for 4/5<ε<12/13, while Hadamard matrices give explicit linear lower bounds for ε<4/5 via a known approximate-rank estimate. We also construct configurations with null squared intervals whose minimum representation dimension remains N−1 for every ε<1. Finally, for every fixed 0<ε<3/5, we show that the quadratic dependence on the parameter C in the dimension bound derived from Deng et al.'s pseudo-Euclidean Johnson-Lindenstrauss lemma is necessary up to a logarithmic factor.
Related
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- Local rigidity of conformally Euclidean metrics for the anisotropic Calderón problem
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- A relative Euclidean thickening
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BibTeX
@misc{muravya2026dimension,
title = {{Dimension Thresholds for Relative-Error Representations of Finite Metrics in Pseudo-Euclidean Spaces}},
author = {Nikita Muravya and Aleksandr Bespalov and Anna Vozianova},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.24254},
eprint = {2610.24254},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.24254},
}
RIS
TY - UNPB
TI - Dimension Thresholds for Relative-Error Representations of Finite Metrics in Pseudo-Euclidean Spaces
AU - Nikita Muravya
AU - Aleksandr Bespalov
AU - Anna Vozianova
PY - 2026
DA - 2026/10/16
PB - arXiv
DO - 10.48550/arxiv.2610.24254
UR - https://arxiv.org/abs/2610.24254
AB - A finite metric space with N points admits an exact representation in a pseudo-Euclidean space of dimension at most N−1. We study the minimum dimension required for relative-error approximation of squared distances. Our main result gives an upper bound for arbitrary metrics in terms of local distance ratios: for 4/5<ε<1, dimension O((N/k)log N+kρ_k^4log N/(ε−4/5)^2) suffices, where ρ_k is the largest ratio, over all points, between the distance to the kth closest point (counting the point itself) and the nearest-neighbour distance. The proof combines a low-rank landmark approximation with a sparse correction controlled by its factorization norm. For metrics with distances in [1,Φ], where Φ≥5 is fixed, the worst-case dimension is Θ(N) for 0<ε<4/5, lies between Ω(√N) and O(√Nlog N) for 4/5<ε<12/13, and is Θ(log N) for ε>(Φ^2−1)/(Φ^2+1). For Φ>5, an intermediate range remains without matching bounds. Sign-pattern counting yields the Ω(√N) lower bound for 4/5<ε<12/13, while Hadamard matrices give explicit linear lower bounds for ε<4/5 via a known approximate-rank estimate. We also construct configurations with null squared intervals whose minimum representation dimension remains N−1 for every ε<1. Finally, for every fixed 0<ε<3/5, we show that the quadratic dependence on the parameter C in the dimension bound derived from Deng et al.'s pseudo-Euclidean Johnson-Lindenstrauss lemma is necessary up to a logarithmic factor.
ER -