Sets which are not tube null and intersection properties of random measures

TL;DR

This paper constructs specific unrectifiable sets in Euclidean space that are not tube null, using random fractal measures and intersection properties, thereby answering longstanding questions and contrasting with Lipschitz-null sets.

Contribution

It introduces the first examples of unrectifiable sets of dimension d-1 that are not tube null, using a novel probabilistic approach and extending to convex tube null sets.

Findings

Existence of unrectifiable sets not tube null in 

Construction of such sets using random fractal measures

Contrast with Lipschitz-null sets established

Abstract

We show that in $\mathbb{R}^d$ there are purely unrectifiable sets of Hausdorff (and even box counting) dimension $d-1$ which are not tube null, settling a question of Carbery, Soria and Vargas, and improving a number of results by the same authors and by Carbery. Our method extends also to "convex tube null sets", establishing a contrast with a theorem of Alberti, Cs\"{o}rnyei and Preiss on Lipschitz-null sets. The sets we construct are random, and the proofs depend on intersection properties of certain random fractal measures with curves.