278 research outputs found
Interruption of torus doubling bifurcation and genesis of strange nonchaotic attractors in a quasiperiodically forced map : Mechanisms and their characterizations
A simple quasiperiodically forced one-dimensional cubic map is shown to
exhibit very many types of routes to chaos via strange nonchaotic attractors
(SNAs) with reference to a two-parameter space. The routes include
transitions to chaos via SNAs from both one frequency torus and period doubled
torus. In the former case, we identify the fractalization and type I
intermittency routes. In the latter case, we point out that atleast four
distinct routes through which the truncation of torus doubling bifurcation and
the birth of SNAs take place in this model. In particular, the formation of
SNAs through Heagy-Hammel, fractalization and type--III intermittent mechanisms
are described. In addition, it has been found that in this system there are
some regions in the parameter space where a novel dynamics involving a sudden
expansion of the attractor which tames the growth of period-doubling
bifurcation takes place, giving birth to SNA. The SNAs created through
different mechanisms are characterized by the behaviour of the Lyapunov
exponents and their variance, by the estimation of phase sensitivity exponent
as well as through the distribution of finite-time Lyapunov exponents.Comment: 27 pages, RevTeX 4, 16 EPS figures. Phys. Rev. E (2001) to appea
In-beam γ-ray spectroscopy of 136Te at relativistic energies
The reduced transition probability B(E2; 0+ 1 →2+ 1 ) to the first excited 2+ state of the neutron-rich nucleus 136Te, with two protons and two neutrons outside the doubly magic 132Sn core, was measured via Coulomb excitation at relativistic energies at the RIKEN Radioactive Isotope Beam Factory. A value of B(E2)= 0.191(26) e2b2 was extracted from the measured inelastic scattering cross section on an Au target taking into account the contributions from both Coulomb and nuclear excitations. In addition, an upper limit for the transition strength to a 2+ state of mixed-symmetry character in the excitation energy range of 1.5–2.2 MeV was determined and compared to the predictions of various theoretical calculations. Because of the high statistics gathered in the present experiment the error of the deduced B(E2) value is dominated by the systematic uncertainties involved in the analysis of Coulomb excitation experiments at beam energies around 150 MeV/u. Therefore, the latter are for the first time assessed in detail in the present work.Spanish Ministerio de Economía y Competitividad (FPA2014-57196-C5-4-P, FPA2017-84756-C4-2-P, FIS2014-53448-C2-1-P
Fractal Properties of Robust Strange Nonchaotic Attractors in Maps of Two or More Dimensions
We consider the existence of robust strange nonchaotic attractors (SNA's) in
a simple class of quasiperiodically forced systems. Rigorous results are
presented demonstrating that the resulting attractors are strange in the sense
that their box-counting dimension is N+1 while their information dimension is
N. We also show how these properties are manifested in numerical experiments.Comment: 9 pages, 14 figure
Transit timing variation analysis of the low-mass brown dwarf KELT-1 b
We investigate whether there is a variation in the orbital period of the short-period brown dwarf-mass KELT-1 b, which is one of the best candidates to observe orbital decay. We obtain 19 high-precision transit light curves of the target using six different telescopes. We add all precise and complete transit light curves from open databases and the literature, as well as the available Transiting Exoplanet Survey Satellite (TESS) observations from sectors 17 and 57, to form a transit timing variation (TTV) diagram spanning more than 10 yr of observations. The analysis of the TTV diagram, however, is inconclusive in terms of a secular or periodic variation, hinting that the system might have synchronized. We update the transit ephemeris and determine an informative lower limit for the reduced tidal quality parameter of its host star of Q ′⋆>(8.5±3.9)×106
assuming that the stellar rotation is not yet synchronized. Using our new photometric observations, published light curves, the TESS data, archival radial velocities, and broadband magnitudes, we also update the measured parameters of the system. Our results are in good agreement with those found in previous analyses
Generalized Phase Synchronization in unidirectionally coupled chaotic oscillators
We investigate phase synchronization between two identical or detuned
response oscillators coupled to a slightly different drive oscillator. Our
result is that phase synchronization can occur between response oscillators
when they are driven by correlated (but not identical) inputs from the drive
oscillator. We call this phenomenon Generalized Phase Synchronization (GPS) and
clarify its characteristics using Lyapunov exponents and phase difference
plots.Comment: 4 pages, 5 figure
Visual pattern recognition as a means to optimising building performance?
Visual pattern recognition as a means to optimising building performance
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