63 research outputs found
Renormalization, Thermodynamic Formalism and Quasi-Crystals in Subshifts
We examine thermodynamic formalism for a class of renormalizable dynamical
systems which in the symbolic space is generated by the Thue-Morse
substitution, and in complex dynamics by the Feigenbaum-Coullet-Tresser map.
The basic question answered is whether fixed points of a renormalization
operator \CR acting on the space of potentials are such that the pressure
function \gamma \mapsto \CP(-\gamma V) exhibits phase transitions. This
extends the work by Baraviera, Leplaideur and Lopes on the Manneville-Pomeau
map, where such phase transitions were indeed detected. In this paper, however,
the attractor of renormalization is a Cantor set (rather than a single fixed
point), which admits various classes of fixed points of \CR, some of which do
and some of which do not exhibit phase transitions. In particular, we show it
is possible to reach, as a ground state, a quasi-crystal before temperature
zero by freezing a dynamical system.Comment: The paper was withdrawn from publication due to an error found in
some proof. This is a new version and resubmitted for publication. The
occurance of phase transition is proved for a parameter a<1 and it is proved
there is no phase transition for a>1. For the value a=1 it is still unkow
Central limit theorem for dimension of Gibbs measures for skew expanding maps
We consider a class of non-conformal expanding maps on the -dimensional
torus. For an equilibrium measure of an H\"older potential, we prove an
analogue of the Central Limit Theorem for the fluctuations of the logarithm of
the measure of balls as the radius goes to zero. An unexpected consequence is
that when the measure is not absolutely continuous, then half of the balls of
radius \eps have a measure smaller than \eps^\delta and half of them have a
measure larger than \eps^\delta, where is the Hausdorff dimension of
the measure. We first show that the problem is equivalent to the study of the
fluctuations of some Birkhoff sums. Then we use general results from
probability theory as the weak invariance principle and random change of time
to get our main theorem. Our method also applies to conformal repellers and
Axiom A surface diffeomorphisms and possibly to a class of one-dimensional non
uniformly expanding maps. These generalizations are presented at the end of the
paper
Large deviations for return times in non-rectangle sets for axiom A diffeomorphisms
For Axiom A diffeomorphisms and equilibrium states, we prove a Large
deviations result for the sequence of successive return times into a fixed
Borel set, under some assumption on the boundary. Our result relies on and
extends the work by Chazottes and Leplaideur who considered cylinder sets of a
Markov partition
Thermodynamic formalism for Lorenz maps
For a 2-dimensional map representing an expanding geometric Lorenz at-
tractor we prove that the attractor is the closure of a union of as long as
possible unstable leaves with ending points. This allows to define the notion
of good measures, those giving full measure to the union of these open leaves.
Then, for any H\"older continuous potential we prove that there exists at most
one relative equilibrium state among the set of good measures. Condition
yielding existence are given.Comment: 36 page
Large deviation for return times in open sets for axiom A diffeomorphisms
For axiom A diffeomorphisms and equilibrium state, we prove a Large deviation
result for the sequence of successive return times into a fixed open set, under
some assumption on the boundary. Our result relies on and extends the work by
Chazottes and Leplaideur who where considering cylinder sets of a Markov
partition
RENORMALIZATION, THERMODYNAMIC FORMALISM AND QUASI-CRYSTALS IN SUBSHIFTS.
The paper was withdrawn from publication due to an error found in some proof. This is a new version and resubmitted for publication. The occurance of phase transition is proved for a parameter a1. For the value a=1 it is still unkown.We examine thermodynamic formalism for a class of renormalizable dynamical systems which in the symbolic space is generated by the Thue-Morse substitution, and in complex dynamics by the Feigenbaum-Coullet-Tresser map. The basic question answered is whether fixed points of a renormalization operator \CR acting on the space of potentials are such that the pressure function \gamma \mapsto \CP(-\gamma V) exhibits phase transitions. This extends the work by Baraviera, Leplaideur and Lopes on the Manneville-Pomeau map, where such phase transitions were indeed detected. In this paper, however, the attractor of renormalization is a Cantor set (rather than a single fixed point), which admits various classes of fixed points of \CR, some of which do and some of which do not exhibit phase transitions. In particular, we show it is possible to reach, as a ground state, a quasi-crystal before temperature zero by freezing a dynamical system
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