Classification of one-dimensional chaotic models

Classifying chaotic maps using the relation between a map and its conjugate basic map with uniform invariant distribution is suggested. It is shown that every symmetric one-dimensional chaotic map with two monotonic branches is topologically equivalent to a tent map or a Bernoulli shift. An algorithm for finding a function conjugating two maps is formulated.     

Information flow and maximum entropy measures for 1-D maps

The invariant measures of maximal metric entropy are constructed explicitly for some maps of the interval, by iterating the maps backward. The construction illustrates in a particularly clear way the information flow in simple systems, as well as recently conjectured relationships between dimensions of invariant measures, Lyapunov exponents, and entropies. maps, it is conjectured that the natural measure is the invariant measure with strongest mixing.     

A rigorous partial justification of Greene's criterion

We prove several theorems that lend support to Greene's criterion for the existence or not of invariant circles in twist maps. In particular, we show that some of the implications of the criterion are correct when the Aubry-Mather sets are smooth invariant circles or uniformly hyperbolic. We also suggest a simple modification that can work in the case that the Aubry-Mather sets have nonzero Lyapunov exponents. The latter is based on a closing lemma for sets with nonzero Lyapunov exponents, which may have several other applications.     

Properties of fully developed chaos in one-dimensional maps

We consider single-humped symmetric one-dimensional maps generating fully developed chaotic iterations specified by the property that on the attractor the mapping is everywhere two to one. To calculate the probability distribution function, and in turn the Lyapunov exponent and the correlation function, a perturbation expansion is developed for the invariant measure. Besides deriving some general results, we treat several examples in detail and compare our theoretical results with recent numerical ones. Furthermore, a necessary condition is deduced for the probability distribution function to be symmetric and an effective functional iteration method for the measure is introduced for numerical purposes.     

On global attractors for a class of nonhyperbolic piecewise affine maps

Dynamical behavior of a class of nonhyperbolic discrete systems are considered. These systems are generated by iterating planar maps that are piecewise isometries, and they arise as mathematical models for signal processing, digital filters and modulator dynamics. Planar piecewise isometries may be discontinuous and/or non-invertible. First, the authors consider attraction caused by discontinuity in planar piecewise isometries. Namely, they have shown that the maximal invariant set can induce an invariant measure, and all the Lyapunov exponents are zero under this invariant measure. Second, they discuss various definitions of global attractors and their existence and uniqueness for discontinuous maps, and introduce a few examples in which the attractors are created due to discontinuity. Third, they study the relation between invariance and invertibility for various nonhyperbolic maps, and finally they investigate decomposability of global attractors for certain nonhyperbolic systems.     

Transformation properties of the Lyapunov exponent of dynamical systems under diffeomorphisms

In this paper we present a geometric definition of the Lyapunov exponent on a differential manifold and investigate its transformation properties under changes of coordinates, or, more generally, under diffeomorphisms. The result is that not every diffeomorphism leaves the Lyapunov exponent invariant. A sufficient condition for invariance is the following: the tangent map of the diffeomorphism is bounded exponentially in the curve parameter for any curve in the manifold and any direction in the tangent bundle with basis restricted to this curve. At the end we show that for a free particle there are diffeomorphisms violating this condition, although they are even canonical maps.     

Lyapunov Functions and Cone Families

We describe systematically the relation between Lyapunov functions and nonvanishing Lyapunov exponents, both for maps and flows. This includes a brief survey of the existing results in the area. In particular, we consider separately the cases of nonpositive and arbitrary Lyapunov functions, thus yielding optimal criteria for negativity and positivity of the Lyapunov exponents of linear cocycles over measure-preserving transformations. Moreover, we describe converse results of these criteria with the explicit construction of eventually strict Lyapunov functions for any map or flow with nonzero Lyapunov exponents. We also construct examples showing that in general the existence of an eventually strict invariant cone family does not imply the existence of an eventually strict Lyapunov function.     

Periodic orbits in coupled Henon maps: Lyapunov and multifractal analysis

A powerful algorithm is implemented in a 1-d lattice of Henon maps to extract orbits which are periodic both in space and time. The method automatically yields a suitable symbolic encoding of the dynamics. The arrangement of periodic orbits allows us to elucidate the spatially chaotic structure of the invariant measure. A new family of specific Lyapunov exponents is defined, which estimate the growth rate of spatially inhomogeneous perturbations. The specific exponents are shown to be related to the comoving Lyapunov exponents. Finally, the zeta-function formalism is implemented to analyze the scaling structure of the invariant measure both in space and time.     

Hierarchy of rational order families of chaotic maps with an invariant measure

We introduce an interesting hierarchy of rational order chaotic maps that possess an invariant measure. In contrast to the previously introduced hierarchy of chaotic maps [1–5], with merely entropy production, the rational order chaotic maps can simultaneously produce and consume entropy. We compute the Kolmogorov-Sinai entropy of these maps analytically and also their Lyapunov exponent numerically, where the obtained numerical results support the analytical calculations.     

The Lyapunov Spectrum Is Not Always Concave

We characterize one-dimensional compact repellers having non-concave Lyapunov spectra. For linear maps with two branches we give an explicit condition that characterizes non-concave Lyapunov spectra. The first author was partially supported by Proyecto Fondecyt 11070050. Both authors were partially supported by Research Network on Low Dimensional Systems, PBCT/CONICYT, Chile.     

Invariants and chaotic maps

A one-dimensional mapf(x) is called an invariant of a two-dimensional mapg(x, y) ifg(x, f(x))=f(f(x)). The logistic map is an invariant of a class of two-dimensional maps. We construct a class of two-dimensional maps which admit the logistic maps as their invariant. Moreover, we calculate their Lyapunov exponents. We show that the two-dimensional map can show hyperchaotic behavior.     

THE UNIVERSAL TRANSITION OF PLATEAU STRUCTURE OF LYAPUNOV EXPONENTS

The universal transition of Lyapunov exponents between conservative limit and dissipa-tire limit of nonlinear dynamical system is studied. It is discovered numerically and proved analytically that for homogeneous dissipative two-dimensional maps, along the equal dissi-pation line in parameter space, the Lyapunov exponents of attractor orbits possess a plateau structure and strict symmetry about its plateau value, The ratios between the plateau width and the stable window width of period 1-4 orbits for Henon map are calculated. The result shows that the plateau structure of Lyapunov exponents remains invariant for the attractor orbits belonging to a period doubling bifurcation sequence. This fact reveals a new universal transition behavior between order and chaos when the dissipation of the dynamical system is weakened to zero.     

Two-dimensional solvable chaos

Two methods are proposed to construct two-dimensional chaotic maps. Several examples of exactly solvable chaotic maps and their invariant measures are obtained. They are isomorphic maps of square to square, plane to plane and circle to circle having various symmetry such as uniform, rotational and the quartic rotational symmetry.     

Chaos in low-dimensional hamiltonian maps

Symplectic maps with more than two degrees of freedom constructed by coupling N area-preserving Chiricov-Taylor standard maps are investigated by numerical methods. We find the asymptotic (for N→∞) distribution of the N positive Lyapunov exponents which is attained already for surprisingly small N. To test the errors in calculating Lyapunov exponents from finite parts of trajectories we calculate the fluctuations of the effective Lyapunov exponents as a function of the number of iterations and find a nontrivial decay on time scales decreasing with increasing degree of freedom. These fluctuations are due to clinging of trajectories to regular orbits.     

Hierarchy of Chaotic Maps with an Invariant Measure

We give hierarchy of one-parameter family (, x) of maps at the interval [0, 1] with an invariant measure. Using the measure, we calculate Kolmogorov-Sinai entropy, or equivalently Lyapunov characteristic exponent of these maps analytically, where the results thus obtained have been approved with the numerical simulation. In contrary to the usual one-parameter family of maps such as logistic and tent maps, these maps do not possess period doubling or period-n-tupling cascade bifurcation to chaos, but they have single fixed point attractor for certain values of the parameter, where they bifurcate directly to chaos without having period-n-tupling scenario exactly at those values of the parameter whose Lyapunov characteristic exponent begins to be positive.     

Singular Spectrum of Lebesgue Measure Zero¶for One-Dimensional Quasicrystals

The spectrum of one-dimensional discrete Schr?dinger operators associated to strictly ergodic dynamical systems is shown to coincide with the set of zeros of the Lyapunov exponent if and only if the Lyapunov exponent exists uniformly. This is used to obtain the Cantor spectrum of zero Lebesgue measure for all aperiodic subshifts with uniform positive weights. This covers, in particular, all aperiodic subshifts arising from primitive substitutions including new examples such as e.g. the Rudin–Shapiro substitution. Our investigation is not based on trace maps. Instead it relies on an Oseledec type theorem due to A. Furman and a uniform ergodic theorem due to the author. Received: 3 July 2001 / Accepted: 11 December 2001     

Robustness of Discrete Dynamics via Lyapunov Sequences

For a nonautonomous dynamics with discrete time defined by a sequence of matrices, we give a complete characterization of nonuniform exponential contractions and nonuniform exponential dichotomies in terms of Lyapunov sequences. We note that these include as very special cases uniform exponential contractions and uniform exponential dichotomies. Due to the central role played by these properties in a substantial part of the theory of dynamical systems, in particular in connection with the study of stable and unstable invariant manifolds, it is important to have available optimal characterizations that are more amenable to check whether a given dynamics has such a property. We also obtain inverse theorems that give explicitly Lyapunov sequences for a given contraction or dichotomy. As a nontrivial application, we establish the robustness under sufficiently small linear perturbations both of nonuniform exponential contractions and nonuniform exponential dichotomies. We emphasize that when compared to former work, our proof of the robustness property is much simpler. Partially supported by FCT through CAMGSD, Lisbon.     

Critical Behavior of the Gaussian Model with Periodic Interactions on Diamond—Type Hierarchical Lattices in External Magnetic Fields

The Gaussian spin model with periodic interactions on the diamond-type hierarchical lattices is constructed by generalizing that with uniform interactions on translationally invariant lattices according to a class of substitution sequences.The Gaussian distribution constants and imposed external magnetic fields are also periodic depending on the periodic characteristic of the interaction onds.The critical behaviors of this generalized Gaussian model in external magnetic fields are studied by the exact renormalization-group approach and spin rescaling method.The critical points and all the critical exponents are obtained.The critical behaviors are found to be determined by the Gaussian distribution constants and the fractal dimensions of the lattices.When all the Gaussian distribution constants are the same,the dependence of the critical exponents on the dimensions of the lattices is the same as that of the Gaussian model with uniform interactions on translationally invariant lattices.     

Unified Description on Behavior of Lyapunov Exponent for 1-D Anderson Model Near Band Center

We investigate the behavior for the Lyapunov exponent around the band center in one-dimensional Anderson model with weak disorder. Using a parametrization method we derive the corresponding differential equation and solve the associated invariant distribution. We obtain the coe?cient for the leading correction term for small energy in band center anomaly. A high precision Pade′ approximation formula is applied to fully amend the anomalous behavior of Lyapunov exponent near band center.     

基于最大Lyapunov指数不变性的混沌时间序列噪声水平估计

提出了一种基于最大Lyapunov指数不变性的计算混沌时间序列噪声水平的新方法. 首先分析了噪声对相空间中两点距离的影响, 然后基于最大Lyapunov指数在不同维数的嵌入相空间不变的性质, 建立了估计噪声水平的方法. 仿真计算结果表明, 当噪声水平小于10% 时, 估计值与真实值符合良好. 该方法对噪声分布类型不敏感, 是一种有效的混沌时间序列噪声估计方法.