High-order Accurate Inference on Manifolds
Chengzhu Huang, Anru R. Zhang
TL;DR
The paper develops a framework for high-order statistical inference on Riemannian manifolds by integrating bootstrap methods with Riemannian Newton iterations and curvature-aware coordinate schemes. It uses fixed normal charts, second-order retracts, and double exponential mappings to achieve accurate hypothesis tests and confidence regions for manifold-valued parameters, with explicit distributional guarantees via Edgeworth-type analyses. The methodology is demonstrated across sphere, Stiefel, fixed-rank matrices, and rank-one tensor manifolds, including Gaussian location and barycenter applications, supported by simulation studies. This work enables reliable, high-precision uncertainty quantification in non-Euclidean parameter spaces common in modern data analysis, while highlighting the role of curvature and chart choice in inference.
Abstract
We present a new framework for statistical inference on Riemannian manifolds that achieves high-order accuracy, addressing the challenges posed by non-Euclidean parameter spaces frequently encountered in modern data science. Our approach leverages a novel and computationally efficient procedure to reach higher-order asymptotic precision. In particular, we develop a bootstrap algorithm on Riemannian manifolds that is both computationally efficient and accurate for hypothesis testing and confidence region construction. Although locational hypothesis testing can be reformulated as a standard Euclidean problem, constructing high-order accurate confidence regions necessitates careful treatment of manifold geometry. To this end, we establish high-order asymptotics under a fixed normal chart centered at the true parameter, thereby enabling precise expansions that incorporate curvature effects. We demonstrate the versatility of this framework across various manifold settings-including spheres, the Stiefel manifold, fixed-rank matrices manifolds, and rank-one tensor manifolds-and, for Euclidean submanifolds, introduce a class of projection-like coordinate charts with strong consistency properties. Finally, numerical studies confirm the practical merits of the proposed procedure.
