Marton's conjecture

About 14 years old · traced to

Let GG be a group of bounded exponent, meaning that every element has order bounded by an absolute constant, and let A⊂GA\subset G satisfy ∣A+A∣≤K∣A∣|A+A|\leq K|A|. A subgroup cover is a subgroup MM whose translates cover AA; the size of the cover is the number of translates, and ∣M∣|M| denotes its cardinality.

Marton's conjecture. AA is exp⁡(O(log⁡K))\exp(O(\log K))-covered by a subgroup MM of size at most exp⁡(O(log⁡K))∣A∣\exp(O(\log K))|A|.

This is the bounded-exponent formulation of the polynomial Freiman–Ruzsa conjecture and would improve the quasipolynomial covering and size bounds available in the theorem stated immediately beforehand.

References

Primary source

Tom Sanders, “The structure theory of set addition revisited”, arXiv:1212.0458 (2012).

Progress summary

Refreshed
Claimed solved

A manuscript claims to prove the conjecture for all abelian bounded-exponent groups, but that claim has not been independently verified.

Marton’s conjecture, attributed to Katalin Marton and published by Imre Ruzsa in 1999, asks for polynomial bounds on subgroup covers of small-doubling sets. The stated source evidence concerns the abelian bounded-exponent formulation.

Known results

  • Sanders, 2012: obtained bounds slightly above polynomial.
  • Gowers, Green, Manners, and Tao, 2023: proved the conjecture in the binary-vector-space case, with roughly K12K^{12} cosets and subgroup size at most ∣A∣|A|.
  • Liao, later: reduced the binary-case exponent from 1212 to 99.
  • Tao and collaborators, December 2023: formally verified the binary-case proof in Lean.

Full abelian bounded-torsion claim

Version 22 of a manuscript by Gowers, Green, Manners, and Tao states that for abelian groups of exponent dividing mm, one can cover AA by at most (2K)O(m3)(2K)^{O(m^3)} translates of a subgroup of size at most ∣A∣|A|. This would prove the conjecture for each fixed exponent, but the supplied evidence does not independently verify the manuscript’s proof. A 2026 algorithmic paper treats this structural theorem as its underlying result.

Current status (as of September 2026): The binary-vector-space case is formally verified, while the full abelian bounded-exponent conjecture is claimed by a manuscript but remains unverified; a genuinely nonabelian interpretation remains open.

Sources

Solutions 0

No solutions have been posted yet.