Two-point patterns determined by curves
Abstract
Let be a smooth curve containing the origin. Does every Borel subset of of sufficiently small codimension enjoy a S\'ark\"ozy-like property with respect to , namely, contain two elements differing by a member of ? Kuca, Orponen, and Sahlsten have answered this question in the affirmative for a specific curve with nonvanishing curvature, the standard parabola in . In this article, we use the analytic notion of "functional type", a generalization of curvature ubiquitous in harmonic analysis, to study containment of patterns in sets of large Hausdorff dimension. Specifically, for curve of finite type at the origin, we prove the existence of a dimensional threshold such that every Borel subset of of Hausdorff dimension larger than contains a pair of points of the form with . The threshold we obtain, though not optimal, is shown to be uniform over all curves of a given "type". We also demonstrate that the finite type hypothesis on is necessary, provided either is parametrized by polynomials or is the graph of a smooth function. Our results therefore suggest a correspondence between sets of prescribed Hausdorff dimension and the "types" of two-point patterns that must be contained therein.
Cite
@article{arxiv.2304.02882,
title = {Two-point patterns determined by curves},
author = {Benjamin B. Bruce and Malabika Pramanik},
journal= {arXiv preprint arXiv:2304.02882},
year = {2023}
}