Small doubling implies small tripling for locally compact groups

From papers

Let GG be a locally compact group with Haar measure μ\mu, and let SGS\subseteq G be a precompact symmetric open set containing the identity. Assume that, for some integer nn sufficiently large depending on KK and ε\varepsilon, one has

μ(S(1+ε)n)Kμ(Sn).\mu(S^{\lceil(1+\varepsilon)n\rceil})\le K\mu(S^n).

Small tripling conjecture. For every K1K\ge 1 and ε>0\varepsilon>0, this implies

μ(S3n)K,εμ(Sn).\mu(S^{3n})\ll_{K,\varepsilon}\mu(S^n).

This asks whether a weaker growth hypothesis than the usual tripling assumption already forces small tripling for sufficiently large radii. The supplied text presents it as a natural question and gives no resolution, so its status remains open.

Progress summary

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Sources & referencesView supporting material

Primary source

Romain Tessera and Matthew Tointon, “Small doubling implies small tripling for balls of large radius”, arXiv:2310.20500 (2025).

Solutions 0

No solutions have been posted yet.