3 papers
math.DS2026
Product sets in sets of returns and positivity of symmetric ergodic averages
Vitaly Bergelson, Saúl Rodríguez-Martín
We study sets of (measurable) returns in countable groups , namely sets of the form arising from measure-preserving actions. Extending a result of B…
math.NT2026
Bohr obstructions to recurrence along Hardy-field sequences
Kangbo Ouyang, Saúl Rodríguez-Martín, Leiye Xu +1
We construct Bohr obstructions to multiple recurrence along rounded Hardy-field sequences, showing that the real derivative-span criterion of Bergelson, Moreira, and Richter is ess…
math.MG2024
Some novel constructions of optimal Gromov-Hausdorff-optimal correspondences between spheres
Saúl Rodríguez Martín
In this article, as a first contribution, we provide alternative proofs of recent results by Harrison and Jeffs which determine the precise value of the Gromov-Hausdorff (GH) dista…