Characterizations of countably $n$-rectifiable Radon measures by higher-dimensional Menger curvatures

TL;DR

This paper characterizes countably $n$-rectifiable Radon measures using higher-dimensional Menger curvatures, extending previous work and establishing new links between curvature integrals and measure rectifiability.

Contribution

It extends Meurer's work to characterize countably $n$-rectifiable measures via integral Menger curvature and relates pointwise curvature to $eta$-numbers under density conditions.

Findings

Characterization of rectifiable measures via $\sigma$-finiteness of Menger curvature.

Finiteness of pointwise Menger curvature implies measure rectifiability.

Establishment of a comparability between pointwise Menger curvature and $eta$-numbers under density assumptions.

Abstract

In the late `90s there was a flurry of activity relating $1$-rectifiable sets, boundedness of singular integral operators, the analytic capacity of a set, and the integral Menger curvature in the plane. In `99 Leger extended the results for Menger curvature to $1$-rectifiable sets in higher dimension, as well as to the codimension one case. A decade later, Lerman and Whitehouse, and later Meurer, found higher-dimensional geometrically motivated generalizations of Menger curvature that yield results about the uniform rectifiability of measures and the rectifiability of sets respectively. In this paper, we provide an extension of Meurer's work that yields a characterization of countably $n$-rectifiable measures in terms of $\sigma$-finiteness of the integral Menger curvature. We also prove that a finiteness condition on pointwise Menger curvature proves rectifiability of Radon measures. Finally, motivated by the partial converse of Meurer's work by Kolasinski we prove that under suitable density assumptions there is a comparability between pointwise-Menger curvature and the sum over scales of the centered $\beta$-numbers at a point.