English

Curved Kakeya sets for generic phases in odd dimensions

Classical Analysis and ODEs 2025-09-16 v2

Abstract

We show that for each odd integer n3n\ge 3, there is an open dense subset of H\"ormander phase functions in Rn\mathbb{R}^n for which the associated curved Kakeya sets have Hausdorff dimension at least n+12+dn\frac{n+1}{2} + d_n for some positive dnd_n, thereby exceeding the classical compression threshold. In particular, in R3\mathbb{R}^3, generic H\"ormander phases induce curved Kakeya sets of dimension at least 2+172 + \tfrac17. As an application, on a generic three-dimensional Riemannian manifold, a local Nikodym set has Hausdorff dimension at least 2+172 + \tfrac17. We achieve these results by generalizing the finite contact order condition from Dai--Gong--Guo--Zhang, originally developed in R3\mathbb{R}^3, to arbitrary dimensions. Our bounds are stronger than those of Dai--Gong--Guo--Zhang even in R3\mathbb{R}^3, since we derive curved Kakeya estimates directly via the polynomial method. Moreover, for H\"ormander-type oscillatory integral operators with positive-definite phases of finite contact order, we obtain quantitative improvements in all odd dimensions over the bounds of Guth--Hickman--Iliopoulou, while in three dimensions our oscillatory integral estimate exactly matches the result of Dai--Gong--Guo--Zhang.

Cite

@article{arxiv.2508.17706,
  title  = {Curved Kakeya sets for generic phases in odd dimensions},
  author = {Shaoming Guo and Diankun Liu and Yakun Xi},
  journal= {arXiv preprint arXiv:2508.17706},
  year   = {2025}
}

Comments

37 pages. Minor inaccuracies in the statement of our results have been addressed

R2 v1 2026-07-01T05:04:04.215Z