English

Sidon sets for linear forms

Number Theory 2022-12-14 v3 Combinatorics

Abstract

Let φ(x1,,xh)=c1x1++chxh\varphi(x_1,\ldots, x_h) = c_1 x_1 + \cdots + c_h x_h be a linear form with coefficients in a field F\mathbf{F}, and let VV be a vector space over F\mathbf{F}. A nonempty subset AA of VV is a φ\varphi-Sidon set if, for all hh-tuples (a1,,ah)Ah(a_1,\ldots, a_h) \in A^h and (a1,,ah)Ah (a'_1,\ldots, a'_h) \in A^h, the relation φ(a1,,ah)=φ(a1,,ah)\varphi(a_1,\ldots, a_h) = \varphi(a'_1,\ldots, a'_h) implies (a1,,ah)=(a1,,ah)(a_1,\ldots, a_h) = (a'_1,\ldots, a'_h). There exist infinite Sidon sets for the linear form φ\varphi if and only if the set of coefficients of φ\varphi has distinct subset sums. In a normed vector space with φ\varphi-Sidon sets, every infinite sequence of vectors is asymptotic to a φ\varphi-Sidon set of vectors. Results on pp-adic perturbations of φ\varphi-Sidon sets of integers and bounds on the growth of φ\varphi-Sidon sets of integers are also obtained.

Keywords

Cite

@article{arxiv.2101.01034,
  title  = {Sidon sets for linear forms},
  author = {Melvyn B. Nathanson},
  journal= {arXiv preprint arXiv:2101.01034},
  year   = {2022}
}

Comments

Minor changes and improvements; 16 pages