Abstract
Sliced Optimal Transport (SOT) is a rapidly developing branch of optimal
transport (OT) that exploits the tractability of one-dimensional OT problems.
By combining tools from OT, integral geometry, and computational statistics,
SOT enables fast and scalable computation of distances, barycenters, and
kernels for probability measures, while retaining rich geometric structure.
This paper provides a comprehensive review of SOT, covering its mathematical
foundations, methodological advances, computational methods, and applications.
We discuss key concepts of OT and one-dimensional OT, the role of tools from
integral geometry such as Radon transform in projecting measures, and
statistical techniques for estimating sliced distances. The paper further
explores recent methodological advances, including non-linear projections,
improved Monte Carlo approximations, statistical estimation techniques for
one-dimensional optimal transport, weighted slicing techniques, and
transportation plan estimation methods. Variational problems, such as minimum
sliced Wasserstein estimation, barycenters, gradient flows, kernel
constructions, and embeddings are examined alongside extensions to unbalanced,
partial, multi-marginal, and Gromov-Wasserstein settings. Applications span
machine learning, statistics, computer graphics and computer visions,
highlighting SOT's versatility as a practical computational tool. This work
will be of interest to researchers and practitioners in machine learning, data
sciences, and computational disciplines seeking efficient alternatives to
classical OT.