共查询到20条相似文献,搜索用时 16 毫秒
1.
A. Laforgia X. Leoncini L. Kuznetsov G.M. Zaslavsky 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,20(3):427-440
The advection of passive tracers in a system of 4 identical point vortices is studied when the motion of the vortices is chaotic.
The phenomenon of vortex-pairing has been observed and statistics of the pairing time is computed. The distribution exhibits
a power-law tail with exponent ∼ 3.6 implying finite average pairing time. This exponents is in agreement with its computed
analytical estimate of 3.5. Tracer motion is studied for a chosen initial condition of the vortex system. Accessible phase
space is investigated. The size of the cores around the vortices is well approximated by the minimum inter-vortex distance
and stickiness to these cores is observed. We investigate the origin of stickiness which we link to the phenomenon of vortex
pairing and jumps of tracers between cores. Motion within the core is considered and fluctuations are shown to scale with
tracer-vortex distance r as r
6. No outward or inward diffusion of tracers are observed. This investigation allows the separation of the accessible phase
space in four distinct regions, each with its own specific properties: the region within the cores, the reunion of the periphery
of all cores, the region where vortex motion is restricted and finally the far-field region. We speculate that the stickiness
to the cores induced by vortex-pairings influences the long-time behavior of tracers and their anomalous diffusion.
Received 28 September 2000 and Received in final form 9 February 2001 相似文献
2.
X.-M. Wang Z.-J. Fang J.-F. Zhang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,37(3):417-422
The multiple Devil's staircase, which describes phase-locking
behavior, is observed in a discontinuous nonlinear circle map.
Phase-locked steps form many towers with similar structure in
winding number(W)-parameter(k) space. Each step belongs to a
certain period-adding sequence that exists in a smooth curve. The
Collision modes that determine steps and the sequence of mode
transformations create a variety of tower structures and their
particular characteristics. Numerical results suggest a scaling
law for the width of phase-locked steps in the
period-adding (W=n/(n+i), n,i∈int) sequences, that is,
Δk(n)∝n-τ (τ>0). And the study indicates
that the multiple Devil's staircase
may be common in a class of discontinuous circle maps. 相似文献
3.
X.-G. Chao J. Dai W.-X. Wang D.-R. He 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(3):423-430
This article reports a sudden chaotic attractor change in a system described by a conservative and
dissipative map concatenation. When the driving parameter passes a critical value, the chaotic
attractor suddenly loses stability and turns into a transient chaotic web. The iterations spend
super-long random jumps in the web, finally falling into several special escaping holes. Once in
the holes, they are attracted monotonically to several periodic points. Following Grebogi, Ott, and
Yorke, we address such a chaotic attractor change as a crisis. We numerically demonstrate
that phase space areas occupied by the web and its complementary set (a fat fractal forbidden net)
become the periodic points' “riddled-like” attraction basins. The basin areas are dominated by
weaker dissipation called “quasi-dissipation”. Small areas, serving as special escape holes, are
dominated by classical dissipation and bound by the forbidden region, but only in each periodic
point's vicinity. Thus the crisis shows an escape from a riddled-like attraction basin. This feature
influences the approximation of the scaling behavior of the crisis's averaged lifetime, which is
analytically and numerically determined as 〈τ〉∝(b-b0)γ, where b0
denotes the control parameter's critical threshold, and γ≃-1.5. 相似文献
4.
J. Bhattacharya P.P. Kanjilal 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,13(2):399-403
The correlation coefficient vs. prediction time profile has been widely used to distinguish chaos from noise. The correlation coefficient remains initially
high, gradually decreasing as prediction time increases for chaos and remains low for all prediction time for noise. We here
show that for some chaotic series with dominant embedded cyclical component(s), when modelled through a newly developed scheme
of periodic decomposition, will yield high correlation coefficient even for long prediction time intervals, thus leading to
a wrong assessment of inherent chaoticity. But if this profile of correlation coefficient vs. prediction horizon is compared with the profile obtained from the surrogate series, correct interpretations about the underlying
dynamics are very much likely.
Received 8 March 1999 相似文献
5.
O. Gomes V. M. Mendes D. A. Mendes J. Sousa Ramos 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,57(2):195-199
There is by now a large consensus in modern monetary policy. This consensus has
been built upon a dynamic general equilibrium model of optimal monetary policy as
developed by, e.g., Goodfriend and King [NBER Macroeconomics
Annual 1997 edited by B. Bernanke and J. Rotemberg (Cambridge, Mass.: MIT Press, 1997), pp. 231–282],
Clarida et al. [J. Econ. Lit. 37, 1661 (1999)],
Svensson [J. Mon. Econ. 43, 607 (1999)]
and Woodford [Interest and Prices: Foundations of a
Theory of Monetary Policy (Princeton, New Jersey, Princeton University
Press, 2003)].
In this paper we extend the standard optimal monetary policy model by introducing nonlinearity into the Phillips curve.
Under the specific form of nonlinearity proposed in our paper (which allows for convexity and concavity and secures
closed form solutions), we show that the introduction of a nonlinear Phillips curve into the structure of the standard
model in a discrete time and deterministic framework produces radical changes to the major conclusions regarding
stability and the efficiency of monetary policy.
We emphasize the following main results: (i) instead of a unique fixed point we end up with multiple equilibria; (ii) instead
of saddle-path stability, for different sets of parameter values we may have saddle stability, totally unstable
equilibria and chaotic attractors; (iii) for certain degrees of convexity and/or concavity of the Phillips curve, where
endogenous fluctuations arise, one is able to encounter various results that seem intuitively correct. Firstly, when the
Central Bank pays attention essentially to inflation targeting, the inflation rate has a lower mean and
is less volatile; secondly, when the degree of price stickiness is high, the inflation
rate displays a larger mean and higher volatility (but this is sensitive to the values
given to the parameters of the model); and thirdly, the higher the target value of the
output gap chosen by the Central Bank, the higher is the inflation rate and its
volatility. 相似文献
6.
M. Terraneo B. Georgeot D.L. Shepelyansky 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(1):127-130
We show that dissipative classical dynamics converging to a strange attractor can be simulated on a quantum computer. Such
quantum computations allow to investigate efficiently the small scale structure of strange attractors, yielding new information
inaccessible to classical computers. This opens new possibilities for quantum simulations of various dissipative processes
in nature.
Received 10 August 2002 Published online 29 October 2002
RID="a"
ID="a"e-mail: dima@irsamc.ups-tlse.fr
RID="b"
ID="b"UMR 5626 du CNRS 相似文献
7.
G. Vilasi 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,30(2):207-210
Melnikov-method-based theoretical results are demonstrated concerning the relative effectiveness of any two weak excitations in suppressing homoclinic/heteroclinic chaos of a relevant class of dissipative, low-dimensional and
non-autonomous systems for the main resonance between the chaos-inducing and chaos-suppressing excitations. General analytical
expressions are derived from the analysis of generic Melnikov functions providing the boundaries of the regions as well as
the enclosed area in the amplitude/initial phase plane of the chaos-suppressing excitation where homoclinic/heteroclinic chaos
is inhibited. The relevance of the theoretical results on chaotic attractor elimination is confirmed by means of Lyapunov
exponent calculations for a two-well Duffing oscillator.
Received 21 May 2002 / Received in final form 13 September 2002 Published online 29 November 2002 相似文献
8.
We discuss strange nonchaotic attractors (SNAs) in addition to chaotic and regular attractors in a quasiperiodically driven system with time delays. A route and the associated mechanism are described for a special type of attractor called strange-nonchaotic-attractor-like (SNA-like) through T2 torus bifurcation. The type of attractor can be observed in large parameter domains and it is easily mistaken for a true SNA judging merely from the phase portrait, power spectrum and the largest Lyapunov exponent. SNA-like attractor is not strange and has no phase sensitivity. Conditions for Neimark-Sacker bifurcation are obtained by theoretical analysis for the unforced system. Complicated and interesting dynamical transitions are investigated among the different tongues. 相似文献
9.
J.O. Andersen 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,28(4):389-396
We consider an interacting homogeneous Bose gas at zero temperature in two spatial dimensions. The properties of the system
can be calculated as an expansion in powers of g, where g is the coupling constant. We calculate the ground state pressure and the ground state energy density to second order in the
quantum loop expansion. The renormalization group is used to sum up leading and subleading logarithms from all orders in perturbation
theory. In the dilute limit, the renormalization group improved pressure and energy density are expansions in powers of the
T
2B and T
2Bln(T
2B), respectively, where T
2B is the two-body T-matrix.
Received 19 April 2002 Published online 13 August 2002 相似文献
10.
F. Li B. J. Zhou W. X. Shu H. L. Luo Z. Y. Huang L. Tian 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,50(1):75-80
We study the chaotic dynamics of a parametrically
modulated Josephson junction with quadratic damping. The Melnikov
chaotic criteria are presented. When the perturbation conditions
cannot be satisfied, numerical simulations demonstrate that the
system can step into chaos via a quasi-periodic route with the
increasing of the dc component of the modulation. However, it is
numerically demonstrated that adding a feedback to the system can
effectively suppress the chaos. 相似文献
11.
This Letter proposes a novel three-dimensional autonomous system which has complex chaotic dynamics behaviors and gives analysis of novel system. More importantly, the novel system can generate three-layer chaotic attractor, four-layer chaotic attractor, five-layer chaotic attractor, multilayer chaotic attractor by choosing different parameters and initial condition. We analyze the new system by means of phase portraits, Lyapunov exponent spectrum, fractional dimension, bifurcation diagram and Poincaré maps of the system. The three-dimensional autonomous system is totally different from the well-known systems in previous work. The new multilayer chaotic attractors are also worth causing attention. 相似文献
12.
We study three critical curves in a quasiperiodically driven system with time delays, where occurrence of symmetry-breaking and symmetry-recovering phenomena can be observed. Typical dynamical tongues involving strange nonchaotic attractors (SNAs) can be distinguished. A striking phenomenon that can be discovered is multistability and coexisting attractors in some tongues surrounding by critical curves. The blowout bifurcation accompanying with on-off intermittency can also be observed. We show that collision of attractors at a symmetric invariant subspace can lead to the appearance of symmetry-breaking. 相似文献
13.
A novel three-dimensional autonomous chaotic system generating two, three and four-scroll attractors
Sara Dadras 《Physics letters. A》2009,373(40):3637-3642
In this Letter a novel three-dimensional autonomous chaotic system is proposed. Of particular interest is that this novel system can generate two, three and four-scroll chaotic attractors with variation of a single parameter. By applying either analytical or numerical methods, basic properties of the system, such as dynamical behaviors (time history and phase diagrams), Poincaré mapping, bifurcation diagram and Lyapunov exponents are investigated to observe chaotic motions. The obtained results clearly show that this is a new chaotic system which deserves further detailed investigation. 相似文献
14.
A variety of different dynamical regimes involving strange nonchaotic attractors (SNAs) can be observed in a quasiperiodically forced delayed system. We describe some numerical experiments giving evidences of intertwined basin boundaries (smooth, non-Wada fractal and Wada property) for SNAs. In particular, we show that Wada property, fractality and smoothness can be intertwined on arbitrarily fine scales. This suggests that SNAs can exhibit the final state sensitivity and unpredictable behaviors. An interesting dynamical transition of SNAs together with associated mechanisms from non-Wada fractal to Wada intertwined basin boundaries is examined. A scaling exponent is used to characterize the intertwined basin boundaries. 相似文献
15.
A feasible model is introduced that manifests phenomena intrinsic to iterative complex analytical maps (such as the Mandelbrot set and Julia sets). The system is composed of two alternately excited coupled oscillators. The idea is based on a turn-by-turn transfer of the excitation from one subsystem to another [S.P. Kuznetsov, Example of a physical system with a hyperbolic attractor of the Smale-Williams type, Phys. Rev. Lett. 95 (2005) 144101] accompanied with appropriate non-linear transformation of the complex amplitude of the oscillations in the course of the process. Analytical and numerical studies are performed. Special attention is paid to an analysis of the violation of the applicability of the slow amplitude method with the decrease in the ratio of the period of the excitation transfer to the basic period of the oscillations. The main effect is the rotation of the Mandelbrot-like set in the complex parameter plane; one more effect is the destruction of subtle small-scale fractal structure of the set due to the presence of non-analytical terms in the complex amplitude equations. 相似文献
16.
R. Tomaschitz 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,17(3):523-536
An elementary account on the origins of cosmic chaos in an open and multiply connected universe is given; there is a finite
region in the open 3-space in which the world-lines of galaxies are chaotic, and the mixing taking place in this chaotic nucleus
of the universe provides a mechanism to create equidistribution. The galaxy background defines a distinguished frame of reference
and a unique cosmic time order; in this context superluminal signal transfer is studied. Tachyons are described by a real
Proca field with negative mass square, coupled to a current of subluminal matter. Estimates on tachyon mixing in the geometric
optics limit are derived. The potential of a static point source in this field theory is a damped periodic function. We treat
this tachyon potential as a perturbation of the Coulomb potential, and study its effects on energy levels in hydrogenic systems.
By comparing the induced level shifts to high-precision Lamb shift measurements and QED calculations, we suggest a tachyon
mass of 2.1 keV/c2 and estimate the tachyonic coupling strength to subluminal matter. The impact of the tachyon field on ground state hyperfine
transitions in hydrogen and muonium is investigated. Bounds on atomic transition rates effected by tachyon radiation as well
as estimates on the spectral energy density of a possible cosmic tachyon background radiation are derived.
Received 13 August 1999 and Received in final form 7 February 2000 相似文献
17.
A.N. Pisarchik R. Meucci F.T. Arecchi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,13(3):385-391
The discrete distribution of homoclinic orbits has been investigated numerically and experimentally in a CO2 laser with feedback. The narrow chaotic ranges appear consequently when a laser parameter (bias voltage or feedback gain)
changes exponentially. Up to six consecutive chaotic windows have been observed in the numerical simulation as well as in
the experiments. Every subsequent increase in the number of loops in the upward spiral around the saddle focus is accompanied
by the appearance of the corresponding chaotic window. The discrete character of homoclinic chaos is also demonstrated through
bifurcation diagrams, eigenvalues of the fixed point, return maps, and return times of the return maps.
Received 28 September 2000 and 27 October 2000 相似文献
18.
This Letter presents a new three-dimensional autonomous system with four quadratic terms. The system with five equilibrium points has complex chaotic dynamics behaviors. It can generate many different single chaotic attractors and double coexisting chaotic attractors over a large range of parameters. We observe that these chaotic attractors were rarely reported in previous work. The complex dynamical behaviors of the system are further investigated by means of phase portraits, Lyapunov exponents spectrum, Lyapunov dimension, dissipativeness of system, bifurcation diagram and Poincaré map. The physical circuit experimental results of the chaotic attractors show agreement with numerical simulations. More importantly, the analysis of frequency spectrum shows that the novel system has a broad frequency bandwidth, which is very desirable for engineering applications such as secure communications. 相似文献
19.
A. D. Chepelianskii 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,52(3):389-396
It is shown that a polarized microwave radiation creates directed transport
in an asymmetric antidot superlattice in two dimensional electron gas.
A numerical method is developed that allows to establish the
dependence of this ratchet effect on several parameters relevant
for real experimental studies.
It is applied to the concrete case of a semidisk Galton board
where the electron dynamics is chaotic in the absence of microwave driving.
The obtained results show that strong currents
can be reached at a relatively low microwave power.
This effect opens new possibilities for microwave control of transport
in asymmetric superlattices. 相似文献
20.
Xiujing Han 《Physics letters. A》2009,373(40):3643-3649
By employing a special feedback controlling scheme, a hyperchaotic Lorenz system with the structure of two time scales is constructed. Two kinds of bursting phenomena, symmetric fold/fold bursting and symmetric sub-Hopf/sub-Hopf bursting, can be observed in this system. Their respective dynamical behaviors are investigated by means of slow-fast analysis. In particular, symmetric fold/fold bursting is of focus-focus type, namely, both the up-state and the down-state are stable focus, which is different from the usual fold/fold bursting; Symmetric sub-Hopf/sub-Hopf bursting is also of focus-focus type, which has not been reported in previous work. Furthermore, phase plane analysis has been introduced to explore the evolution details of the fast subsystem for symmetric sub-Hopf/sub-Hopf bursting. With the variation of the parameter, symmetric sub-Hopf/sub-Hopf bursting can evolve to symmetric chaotic bursting or even hyperchaos. 相似文献