Seminars
GALaC organizes or participates in three different regular seminars.
GALaC team seminar
The GALaC team seminar is organized on a regular basis on Friday at 14:00 in the PCRI building (650) at LISN. Recent and up-coming seminars
Plateau Saclay Combinatorics Seminar
The Plateau Saclay Combinatorics Seminar is held on several Mondays at 11am in room Philippe Flajolet (top floor on the left) at LIX. It is co-organized by the Combi team of LIX and the GALaC team. The mailing list for this seminar is combi_lix_lri@services.cnrs.fr. Subscribe to this ...
Plateau Saclay Algorithms Seminar
The Plateau Saclay Algorithms Seminar is held every other Friday afternoon in LIX. This working group is partially supported by Labex DigiCosme (Digital worlds: distributed data, programs and architectures). If you do wish (or not) to receive any emails from this seminar, you can subscribe or unsubscribe from the mailing ...
Non-intersecting paths and the determinant of the distance matrix of a tree
summary:
We present a combinatorial proof of the Graham–Pollak formula for the determinant of the
distance matrix of a tree, via sign-reversing involutions and the Lindström–Gessel–Viennot Lemma.
This is joint work with Emmanuel Briand, Luis Esquivias-Quintero, Álvaro Gutierrez, and Adrián Lillo.
Lattice structures of Gog and Magog triangles
summary:
Gog and Magog triangles are simple combinatorial objects which are equienumerated.
Howewer, the problem of finding an explicit bijection between these has been an
open problem since the 80’s. These are related to other interesting objects such
as alternating sign matrices, plane partitions or aztec diamond tillings.
All ...
Une nouvelle description des treillis m-cambriens
summary:
Les treillis cambriens, introduits par N. Reading en 2006, sont une généralisation du treillis de Tamari, à tout choix d'élément de Coxeter, dans tout groupe de Coxeter fini. Le treillis de Tamari correspond au "type A linéaire". Ces ordres partiels admettent plusieurs descriptions, non trivialement équivalentes. Celles-ci donnent ...Proper conflict-free colourings of graphs
summary: Given a graph \(G\) of maximum degree \(\Delta\), the proper colouring problem asks for the minimum number of colours that can be assigned to the vertices of \(G\) such that no pair of adjacent vertices are given the same colour; it is easy to show that at most \(\Delta ...
Alternating and nondeterministic plane-walking automata
summary: Plane-walking automata were introduced by Salo & Törma to recognise languages of two-dimensional infinite words (subshifts), the counterpart of 4-way finite automata for two-dimensional finite words. We extend the model to allow for nondeterminism and alternation of quantifiers. We prove that the recognised subshifts form a strict subclass of sofic ...
Translations: fr