Incidence Estimates for Tubes in Complex Space
Sarah Tammen, Lingxian Zhang
TL;DR
The paper develops a complex-space incidence theory for δ-tubes, proving complex analogues of the Guth–Solomon–Wang bounds under strong spacing, and uses these results to obtain a discretized Falconer distance bound in $\mathbb{C}^2$ by translating difference sets into tube incidences via auxiliary lines. A two-scale, multiscale induction framework bridges geometric and Fourier analyses, enabling a dichotomy analysis (thin/thick) and a heavy-ball argument to bound the number of rich δ-balls. The results hinge on the construction of almost-$\delta$-caps, complex tube configurations, and a precise volume bound for intersections of δ-neighborhoods of complex lines, with subsections deriving quantitative auxiliary-line intersections and spacing properties. Together, these contribute a finite-field–style incidence theory in complex space and a new angle-based distance-set bound with potential applications to problems involving complex geometries.
Abstract
In this paper, we prove a complex version of the incidence estimate of Guth, Solomon and Wang for tubes obeying certain strong spacing conditions, and we use one of our new estimates to resolve a discretized variant of Falconer's distance set problem in $\mathbb{C}^2$.
