English

Exceptional set estimates for radial projections in $\mathbb{R}^n$

Classical Analysis and ODEs 2024-03-04 v2 Metric Geometry

Abstract

We prove two conjectures in this paper. The first conjecture is by Lund, Pham and Thu: Given a Borel set ARnA\subset \mathbb{R}^n such that dimA(k,k+1]\dim A\in (k,k+1] for some k{1,,n1}k\in\{1,\dots,n-1\}. For 0<s<k0<s<k, we have dim({yRnAdim(πy(A))<s})max{k+sdimA,0}. \text{dim}(\{y\in \mathbb{R}^n \setminus A\mid \text{dim} (\pi_y(A)) < s\})\leq \max\{k+s -\dim A,0\}. The second conjecture is by Liu: Given a Borel set ARnA\subset \mathbb{R}^n, then dim({xRnAdim(πx(A))<dimA})dimA. \text{dim} (\{x\in \mathbb{R}^n \setminus A \mid \text{dim}(\pi_x(A))<\text{dim} A\}) \leq \lceil \text{dim} A\rceil.

Keywords

Cite

@article{arxiv.2208.03597,
  title  = {Exceptional set estimates for radial projections in $\mathbb{R}^n$},
  author = {Paige Bright and Shengwen Gan},
  journal= {arXiv preprint arXiv:2208.03597},
  year   = {2024}
}

Comments

31 pages; we deleted two sections in the previous version (about the new proofs on classical results); we added more details

R2 v1 2026-06-25T01:32:28.698Z