# CMS[ Edit ]

*Announcement:*

Title: **Brackets and cobrackets in topology of surfaces**

Abstract: We discuss Lie-type algebraic operations - brackets, cobrackets, and double brackets - in the module generated by free homotopy classes of loops in a surface. This subject was initially inspired by the study of the Atiyah-Bott Poisson brackets on the moduli spaces of surfaces. Recently, the algebraic operations on loops were related to the Kashiwara-Vergne equations on automorphisms of free Lie algebras.

Lecture 1: Monday, March 25, 2019 at 15:30

Lecture 2: Wednesday, March 27, 2019 at 15:30

Lecture 3: Thursday, March 28, 2019 at 15:30

**For further details click here**

*Announcement:*

Title: **Brackets and cobrackets in topology of surfaces**

Abstract: We discuss Lie-type algebraic operations - brackets, cobrackets, and double brackets - in the module generated by free homotopy classes of loops in a surface. This subject was initially inspired by the study of the Atiyah-Bott Poisson brackets on the moduli spaces of surfaces. Recently, the algebraic operations on loops were related to the Kashiwara-Vergne equations on automorphisms of free Lie algebras.

Lecture 1: Monday, March 25, 2019 at 15:30

Lecture 2: Wednesday, March 27, 2019 at 15:30

Lecture 3: Thursday, March 28, 2019 at 15:30

**For further details click here**

*Announcement:*

**Title**: *The Double Bubble Problem*

**Abstract**: A single round soap bubble provides the least-perimeter way to enclose a given volume of air, as was proved by Schwarz in 1884. The Double Bubble Problem seeks the least-perimeter way to enclose and separate two given volumes of air. Three friends and I solved the problem in Euclidean space in 2000. In the latest chapter, Emanuel Milman and Joe Neeman recently solved the problem in Gauss space (Euclidean space with Gaussian density). The history includes results in various spaces and dimensions, some by undergraduates. Many open questions remain.

*Announcement:*

**Title**: *The Isoperimetric Problem*

**Abstract**: The isoperimetric problem seeks the least-perimeter way to enclose a given volume. Although the answer is well known to be the round sphere in Euclidean and some other spaces, many fascinating open questions remain. Is a geodesic sphere isoperimetric in CP^2? What is the least-perimeter tile of the hyperbolic plane of prescribed area?

*Announcement:*

**Title**: *The Isoperimetric Problem in Spaces with Density*

**Abstract**: Since their appearance in Perelman's 2006 proof of the Poincaré Conjecture, there has been a flood of interest in positive weights or densities on spaces and the corresponding isoperimetric problem. The talk will include recent results and open questions.

*Announcement:*

**Title**: *GRADED GRAPHS AND CENTRAL MEASURES*

**Abstract** :Graded graphs (Bratteli diagrams) as dynamical language; Markov compact of paths, central measures. connection to asymptotic representation theory of locally finite groups, characters as a central measures. limit shape type theorems and generalized law of large numbers.

*Announcement:*

The aim of the workshop is describing major advancements in bothalgebra and number theory, such as the discovery and advancement ofbounded gaps between twin primes, and the progress on word problems forsimple groups. This workshop day aims at explaining some of theseadvancement to graduate and advanced undergraduate students.

**List of speakers:**

- Eli Aljadeff (Technion)
- Alexei Entin (Tel-Aviv University)
- Danny Krashen (Rutgers University)

**Organizer**: Chen Meiri & Danny Neftin

**IF YOU WISH TO TAKE PART, PLEASE REGISTER HERE:**

*Announcement:*

**Title** : *ERGODIC THEORY OF GRADED GRAPHS*

**Abstract**: Principal cocycle, adic structure, theorem of adic realization, absolute (boundaries) for random walks on the groups, combinatorial coding of dynamical systems.

*Announcement:*

**Title**: *THEORY OF FILTRATIONS AND APPLICATIONS*

**Abstract**: Metric and combinatorial invariants of the filtrations standartness, criteria of standartness, and secondary entropy of automorphisms. boundaries and invariant measures for filtrations; projective limits of the simplices.

*Announcement:*

*Announcement:*

More details: TBA...

*Announcement:*

You are invited to the 2019 Summer School:

**Into the forest: group actions on trees and generalizations**

*July 28 – August 1, 2019*

**There will be 5 mini-courses, given by:**

- Indira Chatterji (UNSA)
- Bruno Duchesne (IECL)
- Mark Hagen (UoB)
- Arnaud Hilion (AMU)
- Michah Sageev (Technion)

**Organizer**: Nir Lazarovich