English

Sums and Products of Distinct Sets and Distinct Elements in $\mathbb{C}$

Combinatorics 2010-09-14 v2 Number Theory

Abstract

Let AA and BB be finite subsets of C\mathbb{C} such that B=CA|B|=C|A|. We show the following variant of the sum product phenomenon: If AB<αA|AB|<\alpha|A| and αlogA\alpha \ll \log |A|, then kA+lBAkBl|kA+lB|\gg |A|^k|B|^l. This is an application of a result of Evertse, Schlickewei, and Schmidt on linear equations with variables taking values in multiplicative groups of finite rank, in combination with an earlier theorem of Ruzsa about sumsets in Rd\mathbb{R}^d. As an application of the case A=BA=B we give a lower bound on A++A×|A^+|+|A^\times|, where A+A^+ is the set of sums of distinct elements of AA and A×A^\times is the set of products of distinct elements of AA.

Keywords

Cite

@article{arxiv.0902.3506,
  title  = {Sums and Products of Distinct Sets and Distinct Elements in $\mathbb{C}$},
  author = {Karsten Chipeniuk},
  journal= {arXiv preprint arXiv:0902.3506},
  year   = {2010}
}

Comments

27 pages, Revised with corrections. Accepted by Integers: Electronic Journal of Combinatorial Number Theory

R2 v1 2026-06-21T12:13:40.210Z