30,949 research outputs found
Periodic and Non-Periodic Solutions of a Ricker-type Second-Order Equation with Periodic Parameters
We study the dynamics of the positive solutions of a second-order,
Ricker-type exponential difference equation with periodic parameters. We find
that qualitatively different dynamics occur depending on whether the period p
of the main parameter is odd or even. If p is odd then periodic and
non-periodic solutions may coexist (with different initial values) if the
amplitude of the periodic parameter is allowed to vary over a sufficiently
large range. But if p is even then all solutions converge to an asymptotically
stable limit cycle of period p if either all the odd-indexed or all the
even-indexed terms of the periodic parameter are less than 2, and the sum of
the even terms does not equal the sum of the odd terms. The key idea in our
analysis is a semiconjugate factorization of the above equation into a
triangular system of two first-order equations.Comment: Latest version adds four additional figures and useful discussion of
multistable behavior; 26 pages, 7 figures; Odd-period versus even-period
dichotom
Maps close to identity and universal maps in the Newhouse domain
Given an n-dimensional C^r-diffeomorphism g, its renormalized iteration is an
iteration of g, restricted to a certain n-dimensional ball and taken in some
C^r-coordinates in which the ball acquires radius 1. We show that for any r >/-
1 the renormalized iterations of C^r -close to identity maps of an
n-dimensional unit ball B^n (n >/- 2) form a residual set among all
orientation-preserving C^r -diffeomorphisms B^n \to R^n. In other words, any
generic n-dimensional dynamical phenomenon can be obtained by iterations of C^r
-close to identity maps, with the same dimension of the phase space. As an
application, we show that any C^r-generic two-dimensional map which belongs to
the Newhouse domain (i.e., it has a wild hyperbolic set, so it is not
uniformly-hyperbolic, nor uniformly partially-hyperbolic) and which neither
contracts, nor expands areas, is C^r -universal in the sense that its
iterations, after an appropriate coordinate transformation, C^r -approximate
every orientation-preserving two-dimensional diffeomorphism arbitrarily well.
In particular, every such universal map has an infinite set of coexisting
hyperbolic attractors and repeller
Extinction, periodicity and multistability in a Ricker Model of Stage-Structured Populations
We study the dynamics of a second-order difference equation that is derived
from a planar Ricker model of two-stage (e.g. adult, juvenile) biological
populations. We obtain sufficient conditions for global convergence to zero in
the non-autonomous case. This gives general conditions for extinction in the
biological context. We also study the dynamics of an autonomous special case of
the equation that generates multistable periodic and non-periodic orbits in the
positive quadrant of the plane.Comment: 26 pages, 2 figures - accepted for publication in the Journal of
Difference Equations and Application
Garden-of-Eden states and fixed points of monotone dynamical systems
In this paper we analyze Garden-of-Eden (GoE) states and fixed points of
monotone, sequential dynamical systems (SDS). For any monotone SDS and fixed
update schedule, we identify a particular set of states, each state being
either a GoE state or reaching a fixed point, while both determining if a state
is a GoE state and finding out all fixed points are generally hard. As a
result, we show that the maximum size of their limit cycles is strictly less
than . We connect these results to the
Knaster-Tarski theorem and the LYM inequality. Finally, we establish that there
exist monotone, parallel dynamical systems (PDS) that cannot be expressed as
monotone SDS, despite the fact that the converse is always true
Folding, Cycles and Chaos in Discrete Planar Systems
We discuss the method of folding for discrete planar systems and use it to
establish the existence or non-existence of cycles or chaos in planar systems
of rational difference equations with variable coefficients. These include some
systems that converge to autonomous systems and some that do not; e.g., systems
with periodic coefficients.Comment: To appear in the Journal of Difference Equations and Applications,
2015. Introduces folding for planar systems of nonlinear difference
equations. Latest version adds 2 figures and a comparative analysis of
rational systems. arXiv admin note: text overlap with arXiv:1403.399
Non-hyperbolic ergodic measures for non-hyperbolic homoclinic classes
We prove that for a generic -diffeomorphism existence of a homoclinic
class with periodic saddles of different indices (dimension of the unstable
bundle) implies existence an invariant ergodic non-hyperbolic (one of the
Lyapunov exponents is equal to zero) measure of .Comment: 50 page
Bifurcations of limit cycles of perturbed completely integrable systems
The main purpose of this article is to study from the geometric point of view
the problem of limit cycles bifurcation of perturbed completely integrable
systems.Comment: 35 page
Hidden chaotic attractors and chaos suppression in an impulsive discrete economical supply and demand dynamical system
Impulsive control is used to suppress the chaotic behavior in an
one-dimensional discrete supply and demand dynamical system. By perturbing
periodically the state variable with constant impulses, the chaos can be
suppressed. It is proved analytically that the obtained orbits are bounded and
periodic. Moreover, it is shown for the first time that the difference
equations with impulses, used to control the chaos, can generate hidden chaotic
attractors. To the best of the authors knowledge, this interesting feature has
not yet been discussed. The impulsive algorithm can be used to stabilize chaos
in other classes of discrete dynamical systems
Products of 2X2 matrices related to non autonomous Fibonacci difference equations
A technique to compute arbitrary products of a class of Fibonacci
square matrices is proved in this work. General explicit solutions for non
autonomous Fibonacci difference equations are obtained from these products. In
the periodic non autonomous Fibonacci difference equations the monodromy
matrix, the Floquet multipliers and the Binet's formulas are obtained. In the
periodic case explicit solutions are obtained and the solutions are analyzed.Comment: 24 pages, 3 figure
Global stability in some one-dimensional non-autonomous discrete periodic population models
For some one-dimensional discrete-time autonomous population models, local
stability implies global stability of the positive equilibrismo point. One of
the known techniques is the enveloping method. In this paper we extend the
enveloping method to one single periodic population models. We show that, under
certain conditions, "individual enveloping" implies "periodic enveloping" in
one-dimensional periodic population models.Comment: 19 pages, 3 figures, original pape
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