🤖 AI Summary
This work addresses the asymptotic theory of Fréchet means and variances on compact Riemannian manifolds, which is typically hindered by the geometric complexity of the cut locus. To circumvent any assumptions on the cut locus, the authors introduce smooth surrogates—termed Varadhan functions, means, and variances—derived from the small-time asymptotics of the Varadhan heat kernel. By integrating tools from differential geometry, probability limit theory, and empirical process methods, they establish a uniform law of large numbers for the empirical versions of these smooth statistics and prove a central limit theorem under a fixed time parameter. Moreover, through a small-time analysis of the gradient and Hessian, they uncover a strong connection between the central limit theorems for Varadhan and Fréchet means, thereby offering new instruments for non-Euclidean statistical inference.
📝 Abstract
Motivated by Varadhan's theorem, we introduce Varadhan functions, variances, and means on compact Riemannian manifolds as smooth approximations to their Fr\'echet counterparts. Given independent and identically distributed samples, we prove uniform laws of large numbers for their empirical versions. Furthermore, we prove central limit theorems for Varadhan functions and variances for each fixed $t\ge0$, and for Varadhan means for each fixed $t>0$. By studying small time asymptotics of gradients and Hessians of Varadhan functions, we build a strong connection to the central limit theorem for Fr\'echet means, without assumptions on the geometry of the cut locus.