Structure of one-dimensional chain-recurrent sets of flows on the 2-sphere and on the plane.
Sturm numbers and substitution invariance of 3iet words.
Subcontinua of inverse limit spaces of unimodal maps
We discuss the inverse limit spaces of unimodal interval maps as topological spaces. Based on the combinatorial properties of the unimodal maps, properties of the subcontinua of the inverse limit spaces are studied. Among other results, we give combinatorial conditions for an inverse limit space to have only arc+ray subcontinua as proper (non-trivial) subcontinua. Also, maps are constructed whose inverse limit spaces have the inverse limit spaces of a prescribed set of periodic unimodal maps as...
Substitution dynamical systems on infinite alphabets
We give a few examples of substitutions on infinite alphabets, and the beginning of a general theory of the associated dynamical systems. In particular, the “drunken man” substitution can be associated to an ergodic infinite measure preserving system, of Krengel entropy zero, while substitutions of constant length with a positive recurrent infinite matrix correspond to ergodic finite measure preserving systems.
Substitution systems associated with the dynamical system (𝒜, Tf)*
We consider the dynamical system (𝒜, Tf), where 𝒜 is a class of differential real functions defined on some interval and Tf : 𝒜 → 𝒜 is an operator Tfφ := fοφ, where f is a differentiable m-modal map. If we consider functions in 𝒜 whose critical values are periodic points for f then, we show how to define and characterize a substitution system associated with (𝒜, Tf). For these substitution systems, we compute the growth rate of the...
Substitutions, abstract number systems and the space filling property
In this paper we study multi-dimensional words generated by fixed points of substitutions by projecting the integer points on the corresponding broken halfline. We show for a large class of substitutions that the resulting word is the restriction of a linear function modulo and that it can be decided whether the resulting word is space filling or not. The proof uses lattices and the abstract number system associated with the substitution.
Substitutions and 1/2-discrepancy of nθ + x
Substitutions commutatives de séries formelles
L’étude des systèmes dynamiques non archimédiens initiée par J. Lubin conduit à déterminer la ramification de séries à coefficients dans un corps fini , qui commutent entre elles pour la loi . Dans cet article nous traitons le cas des sous-groupes abéliens de qui correspondent par le foncteur corps de normes aux extensions abéliennes des extensions finies de , dont la ramification se stabilise dès le début.
Substitutions on two letters, cutting segments and their projections
In this paper we study the structure of the projections of the finite cutting segments corresponding to unimodular substitutions over a two-letter alphabet. We show that such a projection is a block of letters if and only if the substitution is Sturmian. Applying the procedure of projecting the cutting segments corresponding to a Christoffel substitution twice results in the original substitution. This induces a duality on the set of Christoffel substitutions.
Substitutions par des motifs en dimension 1
Une substitution est un morphisme de monoïdes libres : chaque lettre a pour image un mot, et l'image d'un mot est la concaténation des images de ses lettres. Cet article introduit une généralisation de la notion de substitution, où l'image d'une lettre n'est plus un mot mais un motif, c'est-à-dire un “mot à trous”, l'image d'un mot étant obtenue en raccordant les motifs correspondant à chacune de ses lettres à l'aide de règles locales. On caractérise complètement les substitutions par des motifs...
Suites doubles de basse complexité
Nous donnons une représentation géométrique des suites doubles uniformément récurrentes de fonction de complexité rectangulaire . Nous montrons que ces suites codent l’action d’une -action définie par deux rotations irrationnelles sur le cercle unité. La preuve repose sur une étude des suites doubles dont les lignes sont des suite sturmiennes de même langage.
Sur le codage du flot géodésique dans un arbre
Étant donné un arbre et un groupe d’automorphismes de , nous étudions les propriétés markoviennes du flot géodésique sur le quotient de l’espace des géodésiques de par . Par exemple, quand est l’arbre de Bruhat-Tits d’un groupe algébrique linéaire connexe semi-simple de rang 1 sur un corps local non archimédien et si est un réseau (éventuellement non uniforme) dans , nous montrons que l’action des puissances paires de la transformation géodésique est Bernoulli d’entropie finie sur...
Sur les dynamiques holomorphes non linéarisables et une conjecture de V. I. Arnold
Sur les processus quasi-Markoviens et certains de leurs facteurs
We study a class of stationary finite state processes, called quasi-Markovian, including in particular the processes whose law is a Gibbs measure as defined by Bowen. We show that, if a factor with integrable coding time of a quasi-Markovian process is maximal in entropy, then this factor splits off, which means that it admits a Bernoulli shift as an independent complement. If it is not maximal in entropy, then we can find a splitting finite extension of this factor, which generalizes a theorem...
Symbolic discrepancy and self-similar dynamics
We consider subshifts arising from primitive substitutions, which are known to be uniquely ergodic dynamical systems. In order to precise this point, we introduce a symbolic notion of discrepancy. We show how the distribution of such a subshift is in part ruled by the spectrum of the incidence matrices associated with the underlying substitution. We also give some applications of these results in connection with the spectral study of substitutive dynamical systems.
Symbolic dynamics, entropy and complexity of the Feigenbaum map at the accumulation point.
Symbolic dynamics for the Rössler folded towel map
Symbolic extensions in intermediate smoothness on surfaces
We prove that maps with on a compact surface have symbolic extensions, i.e., topological extensions which are subshifts over a finite alphabet. More precisely we give a sharp upper bound on the so-called symbolic extension entropy, which is the infimum of the topological entropies of all the symbolic extensions. This answers positively a conjecture of S. Newhouse and T. Downarowicz in dimension two and improves a previous result of the author [11].
Symmetric CNS trinomials.
Synchronization of nonautonomous dynamical systems.