Bijections for tree-decorated maps and applications to random maps

-- Luis Fredes (LaBRI, Bordeaux)

We introduce a new family of maps, namely tree-decorated maps where the tree is not necessarily spanning. To study this class of maps, we define a bijection which allows us to deduce combinatorial results, recovering as a corollary some results about spanning-tree decorated maps, and to understand local limits. Finally ...

Fighting epidemics with the maximum spectral subgraph

-- Paul Beaujean (GALAC, LRI)

Summary: Recent developments in mathematical epidemiology have identified a relationship between the time to extinction of an epidemic spreading over a network and the spectral radius of the underlying graph i.e. the largest eigenvalue of its adjacency matrix. At the same time, new generation networking technologies such as NFV ...

Self-Stabilization and Byzantine Tolerance for Maximal Matching

-- Laurence Pilard (GALAC, LRI)

Summary: We analyse the impact of transient and Byzantine faults on the construction of a maximal matching in a general network. In particular, we consider the self-stabilizing algorithm called AnonyMatch presented by Cohen et al. in PPL'2016 for computing such a matching. Since self-stabilization is transient fault tolerant, we ...

L-Convex Polyominoes are Recognizable in Real Time by 2D Cellular Automata

-- Anaël Grandjean (Université Paris-Est Créteil)

This is a joint work with Victor Poupet where we investigate the recognition power of cellular automata in real time. A polyomino is said to be L-convex if any two of its cells are connected by a 4-connected inner path that changes direction at most once. The 2-dimensional language representing ...

Reconfiguration Distribuée de Problèmes de Graphes

-- Mikael Rabie (GALAC, LRI)

Summary: En théorie des graphes, un problème de configuration est le suivant : est-il possible d'aller d'une solution valide d'un problème à une autre, en passant par un chemin de solutions acceptables ? Quelle est la longueur minimale d'un chemin ? Quelle est la complexité ? Par exemple, un problème ...

Asymptotic distribution of parameters in random maps

-- Sergey Dovgal (LIPN Univ. Paris 13)

In this joint work with Olivier Bodini, Julien Courtiel, and Hsien-Kuei Hwang, we consider random rooted maps without regard to their genus. We address the problem of limiting distributions for six different parameters: - vertices - leaves - loops - root edges - root isthmic constructions - root vertex degree Each parameter has a different limiting ...

Séminaire ouvert

-- Toute l'équipe (LIX et GALAC)

Lors d'un séminaire ouvert, le thème n'est pas décidé à l'avance. Tous les membres du séminaires sont invités à participer et peuvent proposer le jour même des interventions plus ou moins longues, des démos ou des questions ouvertes au reste de l'équipe.

Séminaire ouvert

-- Toute l'équipe (LIX et GALAC)

Lors d'un séminaire ouvert, le thème n'est pas décidé à l'avance. Tous les membres du séminaires sont invités à participer et peuvent proposer le jour même des interventions plus ou moins longues, des démos ou des questions ouvertes au reste de l'équipe.

Mobius functions for real hyperplane arrangements.

-- Marcelo Aguiar (Cornell Univ.)

We discuss the beginnings of a theory of noncommutative Mobius functions and its connections to the structure of the algebra of faces of a hyperplane arrangement. It is to be seen as a generalization of the theory of Mobius functions for lattices, developed by Rota and his school in the ...

A proof-theoretic analysis of the rotation lattice of binary trees

-- Noam Zeilberger (Birmingham University)

Join seminar with the Parsifal team The classical Tamari lattice Yn is defined as the set of binary trees with n internal nodes, with the partial ordering induced by the (right) rotation operation. It is not obvious why Yn is a lattice, but this was first proved by Haya Friedman ...

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