פעילויות השבוע

A dynamical system is called universal if any system with lower entropy can be embedded into it. In this talk, we will discuss universality for $R^d$ flows $(d>1)$ both in ergodic and Borel contexts. We will discuss a specification property that implies universality for $R^d$ flows and provide an example of a tiling dynamical system with this specification property. This is ongoing work with Tom Meyerovitch. This talk is a preliminary report.

Celebrating Michael Lin‘s 80th birthday. Place: Ben-Gurion university of the Negev. Room -103 in building 14 Mendel building (across from Aroma branch on the west side of the campus). Time: Tuesday 31/5/2022 between 10:30-16:30.

Schedule:

10:00 - 10:30 Coffee 10:30 - 11:20 Omri Sarig (Weizmann institute) 11:40 - 13:00 Jon Aaronson (Tel-Aviv University) 13:00 - 14:30 Lunch (the lunch will take place in room -101 of the math building) 14:30 - 15:20 Eli Glasner (Tel-Aviv University, joint with Colloquium) 15:30 - 16:20 Ariel Yadin (Ben Gurion University)

Organizers: Yair Glasner, Tom Meyerovitch, and Guy Cohen Zoom broadcasting LINK Meeting ID: 820 8565 9434 The conference website: https://sites.google.com/view/michael-lins-80th-birthday/home

Lobachevsky started to work on computing volumes of hyperbolic polytopes long before the first model of the hyperbolic space was found. He discovered an extraordinary formula for the volume of an orthoscheme via a special function called dilogarithm.

We will discuss a generalization of the formula of Lobachevsky to higher dimensions. For reasons I do not fully understand, a mild modification of this formula leads to the proof of a conjecture of Goncharov about the depth of multiple polylogarithms. Moreover, the same construction leads to a functional equation for polylogarithms generalizing known equations of Abel, Kummer, and Goncharov.

Guided by these observations, I will define cluster polylogarithms on a cluster variety.