Workshop on decidable or undecidable problems in dynamical systems
3-5 Jul 2019 Amiens (France)


This meeting will concern dynamical systems, ergodic theory and computability theory with a special focus on the decidability of dynamical properties.

During the last 5 years, numerous results have appeared in large families of dynamical systems: subshifts of finite type, with zero or positive entropy, tilings, domino problems on groups, ...

These topics illustrate the fruitful interactions between mathematics and computer science, where the heart of the matter is decidability problems of some dynamical properties (computation of the entropy, determination of conjugacy, fixed points, optimal strategy,...).

The aim of this conference is to give a state of the art of these topics and to provide an overview of undecidable and effectively decidable dynamical problems. This will facilitate sharing of useful techniques in both areas.

Important dates

The workshop is from the 3rd of July the to the 5th of July 2019.

Talks will start at 10h00 the 3rd and will end at 12h30 the 5th.

Registration is free but mandatory.

Deadline is Thursday 27th of June 2019.

Invited speakers

Mélodie ANDRIEU (Aix-Marseille U.) A semi-algorithm to explore the set of imbalances in S-adic systems

Valérie BERTHE (IRIF, U. Paris Diderot)  Decidability and S-adic dynamics

Emilie CHARLIER (Département de Mathématiques, U. Liège, Belgique) Decidability through first-order logic and regular sequences 

Valérie GOYENECHE (LAMFA, Univ. de Picardie Jules Verne) Recherche de progressions arithmétiques constantes dans les suites substitutives

Pierre-Antoine GUIHENEUF (IMJ, Sorbonne U.) Discrétisations et mesures invariantes : bons ou mauvais amis ?

Benjamin HELLOUIN DE MENIBUS (LRI, U. Paris Sud) Aperiodic points in Z^2-subshifts

Emmanuelle JEANDEL (LORIA, U. de Lorraine) An Aperiodic distance shift

Julien LEROY (Département de Mathématiques, U. Liège, Belgique) Decidability of the isomorphism and the factorization between minimal substitution subshifts 

Glen MERLET (I2M, Aix-Marseille U.) Le rayon spectral joint pour les matrices tropicales est soit fortement polynomial, soit non calculable

Pascal VANIER (LACL, U. Paris Est Créteil) Word complexity and computability in subshifts

Meng WU (Oulu U., Finland) On expansion of numbers in bases 2 and 3

The place to be

The conference will take place at the Universities of Picardie Jules Verne (UPJV):

UFR des sciences

33 rue Saint Leu, Amiens


See the map :


Some hotels close to the university are:

Appart City Amiens : In this hotel, if we make the reservation for you a special rate will be applied : 59,50 euros/night breakfast included

Hotel Victor Hugo

Hotel Spatial

Le Saint Louis





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