Badly approximable points on non-linear carpets
Number Theory
2026-03-13 v1 Dynamical Systems
Metric Geometry
Abstract
The badly approximable points in are those for which Dirichlet's approximation theorem cannot be improved by more than a constant, that is, they are the points most difficult to approximate by rational vectors. An important problem in Diophantine approximation is to determine when the set of badly approximable points intersects a given set in full dimension. We find the first class of non-linear non-conformal attractors for which this full intersection property holds, thus answering a question of Das-Fishman-Simmons-Urba\'nski from 2019. We also provide a formula for the Hausdorff dimension of these attractors which is of independent interest.
Cite
@article{arxiv.2603.11822,
title = {Badly approximable points on non-linear carpets},
author = {Roope Anttila and Jonathan M. Fraser and Henna Koivusalo},
journal= {arXiv preprint arXiv:2603.11822},
year = {2026}
}
Comments
23 pages, 1 figure. Comments are appreciated!