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arXiv · 2207.00053

Intersective sets over abelian groups

Zixiang Xu·Chi Hoi Yip
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Abstract

Given a finite abelian group $G$ and a subset $J\subset G$ with $0\in J$, let $D_{G}(J,N)$ be the maximum size of $A\subset G^{N}$ such that the difference set $A-A$ and $J^{N}$ have no non-trivial intersection. Recently, this extremal problem has been widely studied for different groups $G$ and subsets $J$. In this paper, we generalize and improve the relevant results by Alon and by Heged\H{u}s by building a bridge between this problem and cyclotomic polynomials with the help of algebraic graph theory. In particular, we construct infinitely many non-trivial families of $G$ and $J$ for which the current known upper bounds on $D_{G}(J, N)$ can be improved exponentially.

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Zixiang Xu, Chi Hoi Yip. 2022-06-30. Intersective sets over abelian groups. https://doi.org/10.1007/s10623-025-01760-3

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