Category Archives: Events

2021 Chapel Hill Ergodic Theory Workshop: Global Online Edition

2021 Chapel Hill Ergodic Theory Workshop: Global Online Edition

The activities of the Virtual Ergodic Conference will take place in three consecutive weeks, from June 21 to July 9, 2021. While schedules are thought to adapt most time zones, these are specially fitted to North & South America (week 1), Europe & Africa (week 2) and Asia & Australia (week 3). The format will try to preserve the atmosphere of the Chapel Hill Ergodic Theory Workshops with some adaptations to match current virtual modalities.

Week 1- North & South America
Monday June 21 and Tuesday June 22
Plenary Speakers: Idris Assani; Anush Tserunyan

Week 2- Europe/Africa
Monday June 28 and Tuesday June 29
Plenary Speakers: Tanja Eisner; Mark Pollicott

Week 3- Asia and Australia
Monday July 5 and Tuesday July 6
Plenary Speakers: Danijela Damjanovic; Corinna Ulcigrai; Xiangdong Ye


Schedule of talks:

Organizing Committee:

  • Idris Assani (University of North Carolina at Chapel Hill- USA)
  • Zoltan Buczolich ( Eotvos Lorand University- HUNGARY)
  • Francesco Cellarosi ( Queen’s University – CAD)
  • Tushar Das (University of Wisconsin-Lacrosse- USA)
  • Natalia Jurga (University of St Andrews – UK)
  • Jana Rodriguez Hertz (Southern University of Science and Technology- CHINA)
  • Raul Ures (Southern University of Science and Technology- CHINA)
  • Paulo Varandas ( Federal University of Bahia – Brazil & CMUP – PORTUGAL)

Dynamical systems talk in Milano

Seminario Matematico e Fisico di Milano

Monday June 21, 5pm

Link zoom

Speaker: Jacopo De Simoi (University of Toronto)

Title: Dynamical rigidity of convex billiards 

Abstract: Convex billiards are a classical topic in conservative dynamics. Typically, their dynamics is qualitatively very intricate, since it showcases a coexistence of hyperbolic dynamics and KAM phenomena. Understanding long-term statistical properties of the dynamics with the current technology is essentially an intractable problem. Here I venture in the opposite direction and I will discuss dynamical inverse problems: how much geometrical information can be extracted from the dynamics? More precisely: what can be deduced about the billiard table if one knows the lengths of all periodic orbits? The quantum version of this question has been famously stated as “Can one hear the shape of a drum?” In this talk I will review the latest results and describe the next steps in this direction. This is a joint project with Vadim Kaloshin.

Online Ph.D. course on translation surfaces, June-July 2021

The University of Pisa offers an online Ph.D. course taught by Mauro Artigiani (Universidad del Rosario, Colombia) and Paolo Giulietti (Università di Pisa) titled “Translation Surfaces: From Geometry to Spectral Theory”.

Description: Translation surfaces are a generalization of flat tori to higher genuses, with rich and interesting geometrical and dynamical properties. In fact, they can be seen both from a complex geometry point of view, stemming from the works of Teichmüller, Ahlfors and Bers, and also from a Euclidean geometry point of view, connecting to the works of the Russian school on low dimensional dynamics. These two different point of views have been fruitfully exploited in the last 50 years to obtain many deep and beautiful results.
In this course, we will introduce translation surfaces motivating their interest. Then, we will survey some of the classical results about them, focusing on the dynamical point of view: the geodesic flow on a translation surface is an important example of a parabolic system, in which nearby points diverge slowly from each other. We will stress the general philosophy of renormalization, which connects the study of the geodesic flow on a surface with the study of the geodesic flow on the moduli space of translation surfaces, which has a chaotic behavior that can be exploited to obtain many information on our initial flow.
Prerequisites are measure theory, some familiarity with complex analysis and functional analysis.
A sketch of the course is as follows:

  1. Introduction, motivation, brief survey of Teichmüller’s theorems;
  2. Basic definitions, examples, Masur’s criterion, Sketch of Kerkhoff, Masur and Smillie;
  3. Veech’s dichotomy, Examples of Veech surfaces (without proofs);
  4. Lyapunov exponents, motivations: Zorich’s asymptotic flag. Forni’s proof of Kontsevich-Zorich conjecture for genus 2;
  5. Detour, an explicit counterexample: the Eierlegende Wollmilchsau;
  6. Sketch of the exponential mixing of the Teichmüller flow (following Avila, Gouëzel and Yoccoz);
  7. An introduction to Transfer Operator Theory;
  8. Ruelle resonances for Pseudo-Anosov transformations.

Practical info: The course will last 5 weeks, for a total of approximately 30 hours. The first lecture will be on the 4th of June at 15,30 (Rome Time). From the 7th of June to the 10th of July the schedule is:
Monday 11,30 – 13,30;
Wednesday 15,30 – 17,30;
Friday 15,30 – 17,30

BEWARE: Due to the Italian tradition of “quarto d’ora accademico” lectures begin 15 minutes after the scheduled time.

The course will be held virtually on Teams, hosted by the University of Pisa. Some of the lectures will be streamed and recorded (for the teachers’ use) via Zoom. Accordingly, the links will be provided both by mailing list and the Teams channel.

If you would like to attend the lectures, write to [email protected] or [email protected].

Hybrid conference at CIRM, 14-18 June 2021

Uniformly and non-uniformly hyperbolic dynamics”
“Systèmes dynamiques uniformément et

non-uniformément hyperboliques
(In honour of Christian Bonatti’s 60th birthday)

14 – 18 June 2021


Plenary talks are planned every afternoon, from 1:30pm to 4:30pm approximately. More information will appear soon on the webpage of the event.