COLLOQUES et SEMINAIRES

(Tous les colloques  sont suivis d'un apéritif au Z-Bar)

Journée Lie et espaces des modules (December 18, 2012)

Schedule:
11:15-12:15 Alexander Stolin, "Towards classification of quantum groups"
13:30-14:30 Olga Kravchenko, "Cluster nature of knots"
15:00-16:00 Benoît Vicedo, "Generalized sine-Gordon models and quantum braided groups"

Abstracts:
Alexander Stolin (Chalmers, Gothenburg)
Towards classification of quantum groups
The aim of my talk is to classify Lie bialgebra structures on finite dimensional simple complex Lie algebras (baby example) and their polynomial extensions. A similar technique can be used for classification of certain classes of quantum groups.

Olga Kravchenko (Université Lyon 1)
Cluster nature of knots
I will discuss connections of knot invariants with cluster algebras of Fomin-Zelevinsky.

Benoît Vicedo (University of Hertfordshire, UK)
Generalized sine-Gordon models and quantum braided groups
I will present the quantized function algebras associated with various examples of generalized sine-Gordon models. These are quadratic algebras of the general Freidel-Maillet type, the classical limits of which reproduce the lattice Poisson algebra recently obtained for these models formulated as gauged Wess-Zumino-Witten models plus an integrable potential. More specifically, I will argue based on these examples that the natural framework for constructing quantum lattice integrable versions of generalized sine-Gordon models is that of affine quantum braided groups.

Tuesday, December 18, 2012, 11:15
Villa Battelle, route de Drize 7
Carouge

"Colloque - Basic Notions"
Anders Karlsson (UniGe)
"The magic of Poisson summation"
Abstract:
In this talk I will describe the classical Poisson summation formula,
dating from the early 19th century. This formula has been an important
tool in many areas of mathematics, and has had a large number of
extraordinary applications. I will describe some of these applications,
including the Basel problem, quadratic reciprocity, and counting the number
of ways an integer may be expressed as a sum of squares.
Time permitting, I will also give a brief indication of the wider
context of so-called trace formulas, where a similar principle is at work.
The talk will be accessible to master students.
Mercredi 19 décembre 2012 à 16h15, salle 17 (Attention jour inhabituel)
Tous les membres de la Section et les étudiants sont les bienvenus,
Ce dernier colloque de l'année sera suivi d'une "party" prévue par les étudiants.

"Séminaire La WiNe"
Tullio Ceccherini-Silberstein (Rome)
"On surjunctivity, I"
Abstract:
We consider the notion of a surjunctive map (and, more generally, of a surjunctive (concrete) category) and the related notion of a surjunctive group (due to W. Gottschalk) in the dynamical setting of cellular automata on groups. We show that residually finite groups are surjunctive (for a large class of categories including those of finite sets, of finite-dimensional vector spaces, and of affine algebraic sets over uncountable algebraically closed fields).
Friday, December 21st, 14h00-14h45, room 623

"Séminaire La WiNe"
Tullio Ceccherini-Silberstein (Rome)
"On surjunctivity, II"
Abstract:
We show that amenable groups and, more generally, sofic groups are surjunctive (for a large class of categories including those of finite sets and of finite-dimensional vector spaces). We finally discuss the notion of a surjunctive subshift and the related problem of the density of periodic configurations in general subshifts.
Friday, December 21st, 15h15 -16h00, room 623

Université de Genève
Section de Mathématiques
2-4, rue du Lièvre
CH-1227 Genève-Acacias
Tél. +4122 379 11 51
Fax +4122 379 11 76
E-mail : Najat.Martinez@unige.ch
Mervat.Cluzeau@unige.ch
Isabelle.Cosandier@unige.ch