Fuglede's conjecture holds in π½pd for p=2, d=8 and p=11, d=3
Abstract
Fuglede's conjecture in π½pd says that a nonempty set tiles by translation if and only if it is spectral. We prove the conjecture in π½28 and π½113. Over π½2 we show more generally that the Fourier support of a nonconstant indicator of density different from one half contains a plane. Consequently every spectral set of density one quarter has a subspace tiling complement. This supplies one of the dimension-eight reductions left by Kadowaki; the others are completed using classified Hadamard matrices and perfect binary codes. In π½29 we prove that every tile is spectral and that every spectral set has power-of-two cardinality. All spectral cardinalities except $64$ are shown to tile, and we give further reductions of the remaining case. We also construct a spectral set of density one eighth whose Fourier support contains no three-dimensional subspace. For π½113 we extend the geometric method of Fallon, Mayeli, and Villano by using moment identities, polynomial plane profiles, weighted incidence counts, and exact finite computations. The computations and their verification programs are described in the appendices.
Related
BibTeX
@misc{ferguson2026fugledes,
title = {{Fuglede's conjecture holds in $\mathbbF_p^d$ for $p=2,\,d=8$ and $p=11,\,d=3$}},
author = {Samuel J. Ferguson and Joshua Iosevich},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.30712},
eprint = {2610.30712},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.30712},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - UNPB
TI - Fuglede's conjecture holds in π½_p^d for p=2, d=8 and p=11, d=3
AU - Samuel J. Ferguson
AU - Joshua Iosevich
PY - 2026
DA - 2026/10/22
PB - arXiv
DO - 10.48550/arxiv.2610.30712
UR - https://arxiv.org/abs/2610.30712
AB - Fuglede's conjecture in π½_p^d says that a nonempty set tiles by translation if and only if it is spectral. We prove the conjecture in π½_2^8 and π½_11^3. Over π½_2 we show more generally that the Fourier support of a nonconstant indicator of density different from one half contains a plane. Consequently every spectral set of density one quarter has a subspace tiling complement. This supplies one of the dimension-eight reductions left by Kadowaki; the others are completed using classified Hadamard matrices and perfect binary codes. In π½_2^9 we prove that every tile is spectral and that every spectral set has power-of-two cardinality. All spectral cardinalities except $64$ are shown to tile, and we give further reductions of the remaining case. We also construct a spectral set of density one eighth whose Fourier support contains no three-dimensional subspace. For π½_11^3 we extend the geometric method of Fallon, Mayeli, and Villano by using moment identities, polynomial plane profiles, weighted incidence counts, and exact finite computations. The computations and their verification programs are described in the appendices.
ER -