Orateurs invites

Journees nationales 2016 GdR Informatique Mathematique

18-20 Janvier 2016, Villetaneuse

Lundi 18 janvier13.15–14.15

Javier Esparza(Universite Technique de Munich, Allemangne)Stochastic Process Creation

Branching processes are stochastic processes modeling the behaviour of populations whose individuals die and reproduce.We have studied some of these processes from a computer science point of view, and considered questions like: How fast canwe compute the probability of extinction (that is, the probability that at some point in time no descendants of the originalprocess are alive)? How much memory is needed in average to simulate a process in a computer? I report on our results,which show some beautiful connections between seemingly unrelated disciplines.

Mardi 19 janvier9.30–10.30

Francisco Santos Leal(Universite de Cantabrie, Espagne)Diameters of polyhedra and simplicial complexes

The Hirsch conjecture, posed in 1957, stated that the graph of a d-dimensional polytope or polyhedron with n facetscannot have diameter greater than n− d . The conjecture itself has been disproved by Klee-Walkup (1967) for unboundedpolyhedra and by Santos (2010) for bounded polytopes, but what we know about the underlying question is quite scarce.Most notably, no polynomial upper bound is known for the diameters that were conjectured to be linear. In contrast, nopolyhedron violating the Hirsch bound by more than 25% is known.

In this talk we review several recent attempts and progress on the question. Some of these work in the world of polyhedraor (more often) bounded polytopes, but some try to shed light on the question by generalizing it to simplicial complexes.In particular, we show that the maximum diameter of arbitrary simplicial complexes is in nΘ(d) , we sketch the proof ofHirsch’s bound for “flag” polytopes (and more general objects) by Adiprasito and Benedetti via “combinatorial segments”,a recent construction of Labbe, Manneville and Santos showing that combinatorial segments in non-flag polytopes can haveexponential length, and a recent construction by Bogart and Kim of paths of almost quadratic length in the context ofsubset partition graphs.

Mardi 19 janvier14.00–15.00

Veronique Cortier(Loria, Nancy)Vote electronique : la logique a la rescousse

Le vote electronique se doit d’offrir les memes garanties que le vote traditionnel a l’urne. Dans ce but, les protocoles de voteelectronique ont recours a des primitives cryptographiques, comme dans le cas plus classique des protocoles d’authentificationou d’echange de clefs. Il est desormais reconnu que tous ces protocoles sont difficiles a concevoir et a verifier. Ainsi, desattaques peuvent etre decouvertes des annees plus tard. Les modeles formels, comme les algebres de processus, les clausesde Horn ou les systemes de contraintes, ont ete utilises avec succes pour analyser automatiquement de nombreux protocoles.Cependant, les protocoles de vote electronique compliquent significativement la tache des outils de verification. En effet, ilsfont appel a des primitives souvent nouvelles et complexes (comme le chiffrement homomorphique), a de nouveaux schemasd’execution et assurent de nouvelles proprietes de securite.

Apres une introduction au vote electronique, nous decrirons differentes techniques d’analyses formelles applicables auvote electronique et les nombreux problemes qui restent a resoudre.

Mercredi 20 janvier9.30–10.30

Joachim von zur Gathen(Bonn-Aachen ICIT, Allemagne)Combinatorics on polynomial equations: do they describe nice varieties?

We consider natural combinatorial questions about systems of multivariate polynomials over a finite field and the varietythat they define over an algebraic closure. Fixing the number of variables, the number of polynomials and the sequence ofdegrees, there are finitely many such systems. We ask: for how many systems is the variety nice? Is that usually the case?

“Nice” can refer to various properties: The system is regular, the variety is a set-theoretic (or ideal-theoretic) completeintersection, it is (absolutely) irreducible, or nonsingular.

All properties usually hold. More precisely, for each of them we present a nonzero obstruction polynomial in thecoefficients of the system so that the property holds when the obstruction does not vanish. The obstructions come withexplicit bounds on their degrees. They yield estimates on the probability for the properties to hold. These probabilitiestend rapidly to 1 with growing field size.

A further important property is non-degeneracy: the variety is not contained in a hyperplane. Somewhat surprisingly,this behaves differently. Fixing the dimension and the degree, most systems (with at least two polynomials) describevarieties that are hypersurfaces in some proper linear subspace. Thus they are highly degenerate.

Joint work with Guillermo Matera.

Programme

Journees nationales 2016 GdR Informatique Mathematique

18-20 Janvier 2016, Villetaneuse

Les pauses cafe, buffets, repas et cocktails ont lieu en salle F003-F004.L’ouverture des journees et tous les exposes ont lieu en amphi D.La presentation des posters a lieu dans le hall de l’Institut Galilee.

Lundi 18 janvier

12h-13h accueil buffet

13h-13h15 Ouverture des journees

13h15-14h15 Javier Esparza Stochastic Process Creation

14h15-15h Elham Kashefi Quantum Verification

15h-15h30 Pause cafe

15h30-16h15 Nicolas Bonichon Quelques resultats sur les spanners geometriques

16h15-17h Emmanuel Jeandel An aperiodic tiling using only 11 different Wang tiles

17h-17h45 Viviane Pons Des relations binaires au treillis de Tamari

17h45-19h15 Posters et cocktail

Mardi 19 janvier

9h30-10h30 Francisco Santos Leal Diameters of polyhedra and simplicial complexes

10h30-11h Pause cafe

11h-11h45 Christian Gentil Les objets fractales : de la conception a la fabrication

11h45-12h30 Christophe NegreApproaches for RSA and (Hyper)elliptic Curve CryptosystemsResistant to Simple Power Analysis

12h30-14h Repas

14h-15h Veronique Cortier Vote electronique : la logique a la rescousse

15h-15h45 Delphine Demange Mechanized Verification of SSA-based Compilers Techniques

15h45-16h15 Pause cafe

16h15-17h Adrien Richard Points fixes et cycles de retroaction dans les reseaux booleens

17h-18hInformations et discussion sur le GDRintervention de Jean Mairesse, directeur adjoint scientifique a l’INS2I

18h-19h30 Posters et cocktail

19h30-20h30 Reunion des responsables de GT salle B 107

Mercredi 20 janvier

9h30-10h30 Joachim von zur GathenCombinatorics on polynomial equations: do they describenice varieties?

10h30-11h Pause cafe

11h-11h45 Alain Couvreur Cryptographie basee sur les codes correcteurs

11h45-12h30 Patrick BaillotImplicit Computational Complexity of Subrecursive FunctionalPrograms, with Applications to Cryptographic Proofs

12h30-14h Repas

14h45-15h30 Pierre Calka Enveloppe convexe de points aleatoires

15h30-16h15 Helene Touzet Algorithmique des structures d’ARN

16h30 Remise de la Legion d’honneur a Brigitte Vallee salle F003-F004

Posters – Lundi 18 Janvier

Journees nationales 2016 GdR Informatique Mathematique

18-20 Janvier 2016, Villetaneuse

Les posters sont presentes dans le hall de l’Institut Galilee.

F Sebastian Barbieri (LIP, ENS Lyon) — The domino problem over fractal subsets between Z and Z2

F Tom Besson (LIFO, U. Orleans) — Discretisation automatique de R2 vers un automate cellulaire

F Matthias Bordron (LURPA, ENS Cachan) — Accroissement de la qualite d’une numerisation 3Drealise par un systeme robotise base sur l’analyse et l’integration d’un mesure multi-systemes externe entemps reel

F Alex Bredariol Grilo (LIAFA, U. Paris Diderot) — QMA with subset state witnesses

F Gregory Chatel (LIGM, U. Paris Est) — Sur des generalisations des objets Catalans et leurs algebresde Hopf

F Hugues De Lassus Saint-Genies (Univ. Perpignan, LIRMM) — Error-free tables for trigonometricfunction evaluation

F Nicolas Duhamel (LIX) — Arithmetique de genre 2

F Bastien Durix (IRIT Toulouse) — Towards Skeleton based Reconstruction: From Projective Skele-tonization to Canal Surface Estimation

F Bin Fang (LIAFA, U. Paris Diderot) — Generic Shape and Numerical Analysis of Free-List Allocator

F Lila Fontes (LIAFA, U. Paris Diderot) — Lower Bound Techniques for Communication Complexity

F Nathanael Francois (TU Dortmund) — Streaming Property Testing of Visibly Pushdown Languages

F Cyril Hugounenq (UVSQ, PRiSM) — Arithmetique Rapide pour la Geometrie et la Cryptologie

F Marie Kerjean (PPS, U. Paris Diderot) — Le contenu calculatoire de la differentielle

F Vincent Le Gallic (LRI) — Design de structures secondaires d’ARN avec contraintes de sequences :une approche globale fondee sur les langages formels

F Jean-Christophe Lechenet (LIST, CEA) — Cut Branches Before Looking for Bugs: Sound Verificationon Slices

F Jeremy Levallois (LIRIS, U. Lyon / LAMA, Chambery) — Scale-Space Feature Extraction on DigitalSurfaces

F Hoang Gia Nguyen (LIPN, U. Paris 13) — Towards distributed verification of parametric real-timesystems

F Tuong-Bach Nguyen (GIPSA) — Hierarchical shape representation with geometric and topologicalguarantees

F Alice Pavaux (LIPN, U. Paris 13) — Types de donnees et types fonctionnels en Ludique

F Vincent Penelle (LIJM, U. Marne la Vallee) — Arbres de piles

F Vincent Picard (IRISA) — Analyse stationnaire des reseaux de reactions : systemes de contraintesen modelisation stochastique

F Kacper Pluta (LIGM, Marne-la-Vallee) — Bijective rigid motions of the 2D Cartesian grid

F Valentina Popescu (LIP, ENS-Lyon) — Towards fast and certified multiple-precision libraries

F Jean-Baptiste Priez (LRI) — Exact enumeration of minimal acyclic automata – Bijection betweenacyclic automata and parking functions

F Ngo Quoc Hoan (LIPN, U. Paris 13) — Harmonic sums and polylogarithms at negative multi-indices

F Simon Theissing (LSV, ENS Cachan) — Predicting traffic load in public transportation networks

F Harny Wang (LORIA, U. Nancy) — Supplementarity for ZX-calculus

Posters – Mardi 19 Janvier

Journees nationales 2016 GdR Informatique Mathematique

18-20 Janvier 2016, Villetaneuse

Les posters sont presentes dans le hall de l’Institut Galilee.

F Wassim Abou-Jaoude (Ibens/ens) — formal derivation of qualitative dynamical models from biochem-ical networks

F Adrien Basso-Blandin (ENS Lyon, Harvard medical school) — A knowledge representation meta-model for rule-based modelling of signaling networks

F Mohamed Mahdi Benmoussa (LIPN, U. Paris 13) — Real-time systems modelling with UML statemachines and coloured Petri nets

F Flavien Breuvart (PPS, U. Paris Diderot) — Vers la modelisation des coeffets

F Thomas Caissard (LIRIS, U. Lyon) — Sur le laplacien discret

F Florent Capelli (IMJ, U. Paris Diderot) — Compilation de formules CNF

F Quentin De Mourgues (LIPN, U. Paris 13) — Rauzy Dynamics, Old and New

F Nicolas De Rugy-Altherre (IMJ, U. Paris Diderot) — Polynomes complets en complexite algebrique

F Berenice Delcroix-Oger (CIMI Toulouse) — Arbres non ambigus et mots colores

F Leonardo Disilvestro (IFRES, Telecom ParisTech) — Quantum Protocols within Spekkens’ Toy Model

F Jeremy Dubut (LSV, ENS Cachan) — Homologie naturelle

F Jordan Emme (I2M, AMU) — Formalisme thermodynamique et substitution de k-bonacci

F Laurent Feuilloley (LIAFA, U. Paris Diderot) — Locally Optimal Load Balancing

F Nathanael Fijalkow (Dpt of Computer Science, Oxford) — Online Space Complexity

F Thibault Godin (LIAFA, U. Paris Diderot) — Reversible Mealy Automata and the Burnside Problem

F Aldo Gonzalez Lorenzo (LSIS Marseille Sud) — Two new measures for the homology groups of dis-crete objects

F Nathan Grosshans (LSV, ENS Cachan et U. Montreal) — An abstract formulation of Neciporuk lowerbound method

F Matei Istoan (CITI Lab, INSA Lyon) — Filters computing just right

F Vincent Juge (LIAFA, U. Paris Diderot) — Generation uniforme des tresses

F Adrien Krahenbuhl (LABRI) — Principe d’accumulation locale pour l’analyse geometrique tubulaireet perspectives en imagerie medicale

F Frederik Mallmann-Trenn (LIENS, ENS Paris) — Distance in the Forest Fire Model. How far areyou from Eve?

F Arthur Nunge (LIGM, U. Paris Est) — Demonstration d’une identite combinatoire entre permuta-tions

F Marie Paindavoine et Bastien Vialla (Orange Caen / LIP, UCB, Lyon, et LIRMM) — Ameliorationde l’efficacite du chiffrement homomorphe

F Arnaud Polette (LSIS Marseille Sud) — Description de forme par graphe s’appuyant sur les courburesdiscretes

F Jean-Florent Raymond (LIRMM) — Beaux ordres et graphes

F Samanta Socci (U. Sienne / U. Paris Diderot) — The number of directed k-convex polyominoes

F Marco Solieri (LIPN, U. Paris 13) — Geometry of interaction and Taylor-expansion of lambda-terms

F Bui Van Chien (LIPN, U. Paris 13) — Structure of Polyzetas and Algorithms to Represent on Tran-scendence Bases of Shuffle and Stuffle Algebras

F Didier Villevalois (LIF, U. Marseilles) — Calcul du differentiel entre politiques de controle d’accesvia sur-reduction

How to arrive here – Comment venir ici

Journees nationales 2016 GdR Informatique Mathematique

18-20 Janvier 2016, Villetaneuse

How to reach the campus by public transportation, starting from Paris:

[Solution 1]: Take a Transilien H train from Gare du Nord (train floor, same level as the street, +2 floorsw.r.t. RER and Metro), making sure that it stops at Epinay–Villetaneuse (most trains do). Go downat Epinay–Villetaneuse station, go out at the exit Villetaneuse–Montmagny (not the Epinay one),and take the shuttle bus 156 (yellow sign) up to its terminus, Arret Universite Paris 13 (“Entree 1” onthe campus map).

[Solution 2]: Take metro 13 (e.g. from Gare St. Lazare) northbound, branch St. Denis, stop at St.Denis Porte de Paris. Take the Tram 8 at its starting station, branch Villetaneuse–Universite,up to its terminus. That’s on the top-right corner of the campus map. Reach “Entree 2” on the map.

Orientation within the campus – Plan du campus

Journees nationales 2016 GdR Informatique Mathematique

18-20 Janvier 2016, Villetaneuse

Coffee breaks, buffets, lunchs and the cocktail will be in room F003-F004 of the Institut Galilee 5 .

The opening of the meeting and all of the seminars will be in amphi D 8 , within the complex of thefour octagonal stand-alone buildings (amphis A-B-C-D).

The posters will be hosted in the hall of the Institut Galilee 5 .

Toilets are in the Institut Galilee only (not in amphi D). A few are on the ground floor, a few more onthe first floor.

EDUROAM is accessible in Institut Galilee (possibly but not surely in amphi D).

Numbers 5 and 8 refer to the legenda of the full-fledged campus maps you may find around.

If you need help, the lab of the organising staff is at the magenta spot on the top part of the map, LIPN,and security staff is next to entrances on the perimeter, and at the entrance of Institut Galilee.

Organisers present at the conference and lab staff are distinguished by red-coloured badges (instead ofblue-colored ones as yours).

pathways

first-floorpathways

buildings