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Fast Algorithms for a New Relaxation of Optimal Transport
Proceedings of Thirty Sixth Conference on Learning Theory, PMLR 195:4831-4862, 2023.
Abstract
We introduce a new class of objectives for optimal transport computations of datasets in high-dimensional Euclidean spaces. The new objectives are parametrized by ρ≥1, and provide a metric space Rρ(⋅,⋅) for discrete probability distributions in Rd. As ρ approaches 1, the metric approaches the Earth Mover’s distance, but for ρ larger than (but close to) 1, admits significantly faster algorithms. Namely, for distributions μ and ν supported on n and m vectors in Rd of norm at most r and any ϵ>0, we give an algorithm which outputs an additive ϵr approximation to Rρ(μ,ν) in time (n+m)⋅poly((nm)(ρ−1)/ρ⋅2ρ/(ρ−1)/ϵ).