English

Line-Plane Incidence Bound in $\mathbb{R}^4$

Combinatorics 2023-12-27 v1

Abstract

We consider an incidence problem in R4\mathbb{R}^4 which asks, for a set of LL lines and a set of SS planes in general position, what the maximum number of line-plane incidences is. A line-plane incidence is defined as a point where a line and a plane intersect. We prove that, when the lines and planes are in a truly 4-dimensional configuration such that no more than L12+ϵL^{\frac{1}{2}+\epsilon} lines are contained in any 2-dimensional surface of degree at most DD and no more than S12+ϵS^{\frac{1}{2}+\epsilon} 2-planes are contained in any 3-dimensional hypersurface of degree at most DD, and if L1/2SLL^{1/2} \ll S \ll L, then for a constant D>1D>1 and an ϵ>0\epsilon>0 there exists a non-trivial upper bound for incidences between lines and planes: L34+12ϵS+LS12+ϵL^{\frac{3}{4}+\frac{1}{2}\epsilon}S + LS^{\frac{1}{2}+\epsilon}. We also prove several supporting lemmas.

Keywords

Cite

@article{arxiv.2312.14986,
  title  = {Line-Plane Incidence Bound in $\mathbb{R}^4$},
  author = {Chao Cheng},
  journal= {arXiv preprint arXiv:2312.14986},
  year   = {2023}
}
R2 v1 2026-06-28T14:00:19.408Z