Equivalence of linear and trilinear Kakeya conjectures in three dimensions
Cristian Rios, Eric T. Sawyer
TL;DR
This work proves the equivalence of the dual Kakeya maximal operator conjecture and its disjoint trilinear dual form in three dimensions by translating the problem into a single-scale Fourier square function framework on the paraboloid and exploiting parabolic rescaling. The authors develop a modulated, single-scale square-function extension theory $\mathcal{E}^{\operatorname{square}}(\otimes_{1}L^{\infty}\rightarrow L^{q};\varepsilon)$ for $q>3$ and show it is equivalent to the linear dual Kakeya conjecture; they also extend the equivalence to the disjoint trilinear setting via a parallel modulated square-function framework. A detailed pigeonholing argument, following Bourgain–Guth and RiSa, is adapted to handle single-scale wavelet projections and three interaction regimes (separated, clustered, dipole) using parabolic rescaling, enabling an absorption-based conclusion that the key single-scale bounds imply the Kakeya conjectures. The results unify linear and trilinear Kakeya phenomena through Fourier-extension techniques on the paraboloid, with potential implications for transverse multilinear Kakeya and related Fourier-analytic problems. The paper thus advances our understanding of Kakeya-type phenomena by linking maximal-operator estimates to square-function and paraboloid-extension frameworks, offering a robust approach for future sharp bounds.
Abstract
We prove the equivalence of two Kakeya conjectures: 1.The Kakeya maximal operator conjecture 2.The disjoint trilinear dual form of the Kakeya maximal operator conjecture
