On Fourier coefficients of sets with small doubling
The electronic journal of combinatorics, Tome 32 (2025) no. 3
Let $A$ be a subset of a finite abelian group such that $A$ has a small difference set $A-A$ and the density of $A$ is small. We prove that, counter-intuitively, the smallness (in terms of $|A-A|$) of the Fourier coefficients of $A$ guarantees that $A$ is correlated with a large Bohr set. Our bounds on the size and the dimension of the resulting Bohr set are close to exact.
DOI :
10.37236/13691
Classification :
11B13, 20K01
Affiliations des auteurs :
Ilya D. Shkredov  1
@article{10_37236_13691,
author = {Ilya D. Shkredov},
title = {On {Fourier} coefficients of sets with small doubling},
journal = {The electronic journal of combinatorics},
year = {2025},
volume = {32},
number = {3},
doi = {10.37236/13691},
zbl = {8097646},
url = {http://geodesic.mathdoc.fr/articles/10.37236/13691/}
}
Ilya D. Shkredov. On Fourier coefficients of sets with small doubling. The electronic journal of combinatorics, Tome 32 (2025) no. 3. doi: 10.37236/13691
Cité par Sources :