×

Finite chains inside thin subsets of \(\mathbb{R}^d\). (English) Zbl 1342.28006

Summary: In [J. Anal. Math. 128, 289–335 (2016; Zbl 1375.28008)], V. Chan et al. investigated geometric configurations inside thin subsets of Euclidean space possessing measures with Fourier decay properties. In this paper we ask which configurations can be found inside thin sets of a given Hausdorff dimension without any additional assumptions on the structure. We prove that if the Hausdorff dimension of \(E \subset \mathbb{R}^d\), \(d \geq 2\), is greater than \(\frac{1}{2}(d+1)\) then, for each \(k \in \mathbb{Z}^+\), there exists a nonempty interval \(I\) such that, given any sequence \(\{t_1, t_2, \dots, t_k: t_j \in I\}\), there exists a sequence of distinct points \({\{x^j\}}_{j=1}^{k+1}\) such that \(x^j \in E\) and \(| x^{i+1}-x^i|=t_j\) for \(1 \leq i \leq k\). In other words, \(E\) contains vertices of a chain of arbitrary length with prescribed gaps.

MSC:

28A75 Length, area, volume, other geometric measure theory
42B10 Fourier and Fourier-Stieltjes transforms and other transforms of Fourier type
53C10 \(G\)-structures

Citations:

Zbl 1375.28008