The Fourier extension conjecture for the paraboloid
Abstract
We give a proof of Fourier extension conjecture on the paraboloid in all dimensions bigger than 2 that begins with a decomposition suggested in Sawyer [Saw8] of writing a smooth Alpert projection as a sum of pieces whose Fourier extensions are localized. This is then used to establish a local inequality that is well known to be equivalent to the Fourier extension conjecture, and is accomplished by using a variant of the bilinear equivalence of the Fourier extension conjecture given by Tao, Vargas and Vega in [TaVaVe]. A key aspect of our proof is that the bilinear inequality, when taken over smooth Alpert projections, only requires an averaging over grids of functions mollified by discrete multipliers, which converts a difficult exponential sum into an oscillatory integral with periodic amplitude. After extracting Dirichlet kernels in yet another averaging over lattices, this is then controlled using a stationary phase estimate with periodic amplitude, and altogether we then obtain the desired localization on the Fourier side.
Keywords
Cite
@article{arxiv.2512.24990,
title = {The Fourier extension conjecture for the paraboloid},
author = {Cristian Rios and Eric T. Sawyer},
journal= {arXiv preprint arXiv:2512.24990},
year = {2026}
}
Comments
57 pages. A systematic misprint regarding one of the smooth cutoff functions psi is corrected throughout the last half of the paper, and the expectation over grids and the averaging over tilings is clarified