MAThS
Mathematical Analysis in Thessaloniki Seminar
Mathematical Analysis in Thessaloniki Seminar
Faculty Members
Postdocs
PhD Students
Angelidou Mary
Papadimitriou Christos
Poursalidis Nikos
Simichanidis Alexandros
Stavropoulos Sokratis
05-11-2025: Mihalis Kolountzakis (University of Crete)
Date: Wednesday 05-11-2025, 12:00pm in room M2
Title: Bounded common fundamental domains for two lattices
Abstract: We prove that for any two lattices $L, M \subseteq \RR^d$ of the same volume there exists a measurable, bounded, common fundamental domain of them. In other words, there exists a bounded measurable set $E \subseteq \RR^d$ such that $E$ tiles $\RR^d$ when translated by $L$ or by $M$. A consequence of this is that the indicator function of $E$ forms a Weyl--Heisenberg (Gabor) orthogonal basis of $L^2(\RR^d)$ when translated by $L$ and modulated by $M^*$, the dual lattice of $M$.
24-09-2025: Andreu Ferré-Moragues (Universidad Complutense de Madrid)
Date: Wednesday 24-09-2025, 10:00am in room M2
Title: Ergodic Ramsey Theory and partition regularity of Pythagorean pairs
Abstract: In this talk we will explore how the analytical tools afforded by Ergodic Theory can be leveraged to tackle problems in Combinatorics; more particularly, Ramsey Theory. After a brief introduction to the main ideas of these topics, we will jump into the problem that will be our focus: partition regularity of Pythagorean pairs. We will understand how the problem was dealt with in previous works of Frantzikinakis, Klurman, and Moreira and discuss an extension to the Gaussian integers. This last bit is part of an ongoing joint project with Sebastián Donoso, Andreas Koutsogiannis and Wenbo Sun.