English

The sum-product conjecture is false for real numbers

Number Theory 2026-05-28 v1 Combinatorics

Abstract

We disprove the sum-product conjecture for real numbers by constructing arbitrarily large ARA\subset \mathbb{R} (whose elements are algebraic integers in a number field of degree logA\asymp \log\lvert A\rvert) such that max(A+A,AA)A2c\max(\lvert A+A\rvert ,\lvert AA\rvert)\leq \lvert A\rvert^{2-c} where c>0c>0 is an absolute constant. We also disprove the many sums and products conjecture by constructing, for any k3k\geq 3, arbitrarily large ARA\subset \mathbb{R} such that max(kA,A(k))AClogkloglogk\max(\lvert kA\rvert,\lvert A^{(k)}\rvert)\leq \lvert A\rvert^{C\frac{\log k}{\log\log k}} for some constant C>0C>0. We obtain similar constructions for pp-adics, finite fields, and function fields in positive characteristic, and also obtain new lower bounds for the number of solutions to linear equations in a multiplicative group and the number of solutions to the unit equation in sufficiently many variables.

Keywords

Cite

@article{arxiv.2605.28781,
  title  = {The sum-product conjecture is false for real numbers},
  author = {Thomas F Bloom and Will Sawin and Carl Schildkraut and Dmitrii Zhelezov},
  journal= {arXiv preprint arXiv:2605.28781},
  year   = {2026}
}

Comments

25 pages

R2 v1 2026-07-22T07:37:45.581Z