3 papers
math.DS2026
Multiple ergodic averages for commuting multiplicative actions
Dimitrios Charamaras, Andreas Koutsogiannis, Konstantinos Tsinas
We study the convergence of multiple ergodic averages involving several commuting multiplicative actions. We prove that for finitely generated systems, the averages $$\frac{1}{N}\s…
math.DS2025
Infinite unrestricted sumsets in subsets of abelian groups with large density
Dimitrios Charamaras, Ioannis Kousek, Andreas Mountakis +1
Let be a countable abelian group such that the subgroup has finite index and the doubling map has finite kernel. We establish lower bo…
math.NT2024
On multiplicative recurrence along linear patterns
Dimitrios Charamaras, Andreas Mountakis, Konstantinos Tsinas
In a recent article, Donoso, Le, Moreira and Sun studied sets of recurrence for actions of the multiplicative semigroup and provided some sufficient conditio…