Quantitative stability in optimal transport for general power costs
Octave Mischler, Dario Trevisan
TL;DR
The paper advances the quantitative stability theory for optimal transport with a broad class of power costs $\mathcal{W}_p$, $p>1$, by deriving explicit $L^2(\rho)$-type bounds that quantify how Kantorovich potentials and OT maps react to perturbations in the target measure. It develops a unified approach that handles quadratic costs and generalizes to $p\ge 2$ and $1<p<2$ via new convexity and interpolation tools, notably a log-concavity-based Prékopa–Leindler extension and fractional Sobolev techniques. The results require a log-concave source $\rho$ with bounded convex support and compact target supports (or moment bounds), with explicit exponents depending on $p$, providing practical insights for numerical stability and semi-discrete analyses. Overall, the work broadens the stability framework beyond quadratic costs and offers precise, implementable rates that can inform algorithm design and error estimates in OT-based applications.
Abstract
We establish novel quantitative stability results for optimal transport problems with respect to perturbations in the target measure. We provide explicit bounds on the stability of optimal transport potentials and maps, which are relevant for both theoretical and practical applications. Our results apply to a wide range of costs, including all Wasserstein distances with power cost exponent strictly larger than $1$ and leverage mostly assumptions on the source measure, such as log-concavity and bounded support. Our work provides a significant step forward in the understanding of stability of optimal transport problems, as previous results where mostly limited to the case of the quadratic cost.
