Other info
Organizers:
Riccardo
Biagioli
Frédéric
Jouhet
Jiang Zeng
Institut Camille Jordan
Université Claude
Bernard Lyon 1
Contact:
slc58 (at) math (dot) univ-lyon1 (dot) fr
58th Séminaire Lotharingien de Combinatoire
March 18-21,
2007
Domaine
des Hautannes
33 rue du 8 Mai
F-69650 St.Germain au Mont D'Or, Lyon (FRANCE)
Tel.: +33 - (0)4 78 91 25 29
Fax.: +33 - (0)4 72 08 99 26
Participants are expected to arrive for dinner on Sunday and leave after lunch on Wednesday, or Thursday evening if they plan to attend the "Groupe de travail jeunes chercheurs".
Participants will be housed in double rooms or in single rooms. The rates are the following:
On a double
occupancy basis: 75 Euros (board and lodging) per
person (per day).
On a single
occupancy basis: 90 Euros (board and lodging) per person
(per day).
The main
speakers of this session will be:
Frédéric
Chapoton (Université Claude Bernard Lyon
1)
Operads and Algebraic Combinatorics of Trees
We will present various combinatorial aspects of the algebraic notion
of
operad, which is closely related to the theory of species. We plan to
introduce carefully the necessary algebraic background and to
concentrate then on specific operads defined on different kinds of
trees. Among the combinatorial objects involved, one can find posets,
bijections and statistics.
Hjalmar
Rosengren (Chalmers University of Technology)
Applications of Pfaffians in Number Theory and Combinatorics
In 1994, Kac and Wakimoto used the theory of affine superalgebras to
prove
and conjecture several remarkable families of elliptic function
identities, some of which can be viewed as pfaffian evaluations. These
results were used to find new formulas for the number of
representations
of an integer as a sum of a fixed number of squares or triangles. We
will
survey our recent work that emerged from trying to understand Zagier's
proof of one of their conjectures, and extending it to find new proofs
of
Milne's sums of squares formulas. This turns out to have unexpected
relations to several areas of mathematics: Schur Q-polynomials and
marked
shifted tableaux, q-orthogonal polynomials, correlation functions for
random hermitian matrices, and enumeration of symmetry classes of
alternating sign matrices.
We also welcome
contributed talks for the conference. If you are
interested in giving a talk, please indicate a title in your
registration
form by February 26th, 2007.
Groupe de travail jeunes chercheurs en Combinatoire Algébrique
March 21-22,
2007
Joint with SLC 58, and within the program GDR - Informatique Mathématique, we organize a workshop in "Algebraic Combinatorics" targeted at graduate students. This meeting shall familiarize young researchers with several directions of this active area of research. At the same time, it will give them the opportunity to exchange knowledge, and stimulate contacts.
Three
introductory lectures will be given by:
- Julien Cassaigne (Institut de Mathématiques de Luminy)
- Sylvie Corteel (LRI - Université Paris Sud)
- Jean-Christophe Novelli (Université de Marne-la-Vallée).
The remaining time will be devoted to student's talks. So we encourage graduate students to participate and to speak.
All usual SLC
participants are welcome to stay and communicate this event to their
students.
Financial support. We have a limited amount devoted to partially support graduate students. Applicants may request support to attend the workshop alone, or a combination of the workshop and the 58th Séminaire Lotharingien de Combinatoire. To apply send us a request together with your registration form.