Séminaire Lotharingien de Combinatoire, B61pref (2008), 1 p.

Carlos André, Olga Azenhas, António Guedes de Oliveira, Ricardo Mamede

Preface

The 61st Meeting of the Séminaire Lotharingien de Combinatoire took place in the XIXth century building of Grande Hotel da Curia, from September 21 to September 24, 2008. It was the first time that the Séminaire met in Portugal.

Wednesday afternoon was added to the programme to allow for enough time to those coming far from here. However, despite this extra afternoon, a poster session had to be included in the programme due to the large number of proposed talks. Participants were expected to arrive for dinner on Sunday and leave after breakfast on Thursday.

The Séminaire was dedicated to the memory of Pierre LEROUX (1942-2008). In particular, the Tuesday afternoon session was reserved for talks given by some of his closest friends, namely Gilbert Labelle, Amel Kaouche, Nantel Bergeron, and Xavier Viennot. It was chaired by another of his closest friends, Srecko Brlek. After dinner, Christian Krattenthaler marvelled us with a piano recital, where he played the Sonata in F major, K 332, by Wolfgang Amadeus Mozart and the Sonata in A major, D 959, by Franz Schubert.

The two series of main lectures were given by

Anders BJÖRNER (KTH, Stockholm)
"Three Topics in Topological Combinatorics"

and

Ron KING (University of Southampton)
"Schur Functions and Characters of Lie Algebras and Superalgebras"

We are grateful to CMUC (Centre for Mathematics of University of Coimbra), CELC (Centro de Estruturas Lineares e Combinatórias), CMUP (Centro de Matemática da Universidade do Porto), FCT (Fundação para a Ciência e a Tecnologia), for their substantial financial support; and to the Department of Mathematics, Faculty of Science and Technology, University of Coimbra, for the generous organisational support.

Finally, we wish to thank both the speakers and the authors of the posters presented, all those who proposed talks but by various reasons could not come, and all the participants, who, together, made this edition of the Séminaire a significant success.

Contributed talks:

Ron ADIN: Triangle-free triangulations

Carlos ANDRÉ: Combinatorial aspects of supercharacter theories of unitriangular groups

Nantel BERGERON: Isometry classes of generalized associahedra

Emmanuel BRIAND: Piecewise quasipolynomial formulas for Kronecker coefficients indexed by two-row shapes

Glória CRAVO: Logical termination of workflows: an interdisciplinary approach

Mark DUKES: Permutations, (2+2)-free posets, and ascent sequences

Guo-Niu HAN: A promenade in the garden of hook length formulas

Matthieu JOSUAT-VERGÈS: Rook placements in Young diagrams

Amel KAOUCHE: Invariants de graphes liés aux gaz imparfaits

Roman KÖNIG: Some remarks on partition lattices

Christoph KOUTSCHAN: Proof of Ira Gessel's lattice path conjecture

Gilbert LABELLE: General combinatorial differential operators

Ana Filipa LOUREIRO: Inverse relations between powers of Bochner's operator and a differential operator of any even order

István MEZÖ: r-Stirling numbers, Whitney numbers, and their common generalization

Yuval ROICHMAN: Flag orders

Ilda PEREZ DA SILVA: Orientability of cubes

Michael SCHLOSSER: An elliptic generalization of the quantum binomial theorem

Heesung SHIN: Forests and parking functions

Xavier VIENNOT: Hommage à mon ami Pierre Leroux, Alternative tableaux, permutations, a Robinson-Schensted like bijection, and the asymmetric exclusion process in physics

Jiang ZENG: Combinatorics of q-Charlier and q-Laguerre polynomials

Posters:

Fabrizio CASELLI: Quasi-reflection groups

Federico INCITTI: Kazhdan-Lusztig polynomials, rooted partitions and quasi-minuscule quotients

Mercedes ROSAS: Nilpotent matrices and a counterexample to a conjecture of Weyman

Christian STUMP: Non-crossing partitions, non-nesting partitions and Coxeter sortable elements in types A and B

List of Participants: