3,603 research outputs found
Noiseless Collective Motion out of Noisy Chaos
We consider the effect of microscopic external noise on the collective motion
of a globally coupled map in fully desynchronized states. Without the external
noise a macroscopic variable shows high-dimensional chaos distinguishable from
random motion. With the increase of external noise intensity, the collective
motion is successively simplified. The number of effective degrees of freedom
in the collective motion is found to decrease as with the
external noise variance . It is shown how the microscopic noise can
suppress the number of degrees of freedom at a macroscopic level.Comment: 9 pages RevTex file and 4 postscript figure
Investment behaviour of machine-building enterprises and the capital cost
The formation of an effective financial and investment model of engineering production requires the organization of capital cost management. This article is intended to consider the extent to which the features of the investment behaviour of Russian engineering enterprises affect the cost of capital. © Published under licence by IOP Publishing Ltd
On the susceptibility function of piecewise expanding interval maps
We study the susceptibility function Psi(z) associated to the perturbation
f_t=f+tX of a piecewise expanding interval map f. The analysis is based on a
spectral description of transfer operators. It gives in particular sufficient
conditions which guarantee that Psi(z) is holomorphic in a disc of larger than
one. Although Psi(1) is the formal derivative of the SRB measure of f_t with
respect to t, we present examples satisfying our conditions so that the SRB
measure is not Lipschitz.*We propose a new version of Ruelle's conjectures.* In
v2, we corrected a few minor mistakes and added Conjectures A-B and Remark 4.5.
In v3, we corrected the perturbation (X(f(x)) instead of X(x)), in particular
in the examples from Section 6. As a consequence, Psi(z) has a pole at z=1 for
these examples.Comment: To appear Comm. Math. Phy
On the computational content of Zorn's lemma
We give a computational interpretation to an abstract instance of Zorn's
lemma formulated as a wellfoundedness principle in the language of arithmetic
in all finite types. This is achieved through G\"odel's functional
interpretation, and requires the introduction of a novel form of recursion over
non-wellfounded partial orders whose existence in the model of total continuous
functionals is proven using domain theoretic techniques. We show that a
realizer for the functional interpretation of open induction over the
lexicographic ordering on sequences follows as a simple application of our main
results
Excitations in the Halo Nucleus He-6 Following The Li-7(gamma,p)He-6 Reaction
A broad excited state was observed in 6-He with energy E_x = 5 +/- 1 MeV and
width Gamma = 3 +/- 1 MeV, following the reaction Li-7(gamma,p)He-6. The state
is consistent with a number of broad resonances predicted by recent cluster
model calculations. The well-established reaction mechanism, combined with a
simple and transparent analysis procedure confers considerable validity to this
observation.Comment: 3 pages of LaTeX, 3 figures in PostScript, approved for publication
in Phys. Rev. C, August, 200
Periodicity Manifestations in the Turbulent Regime of Globally Coupled Map Lattice
We revisit the globally coupled map lattice (GCML). We show that in the so
called turbulent regime various periodic cluster attractor states are formed
even though the coupling between the maps are very small relative to the
non-linearity in the element maps.
Most outstanding is a maximally symmetric three cluster attractor in period
three motion (MSCA) due to the foliation of the period three window of the
element logistic maps. An analytic approach is proposed which explains
successfully the systematics of various periodicity manifestations in the
turbulent regime. The linear stability of the period three cluster attractors
is investigated.Comment: 34 pages, 8 Postscript figures, all in GCML-MSCA.Zi
Theory and computation of covariant Lyapunov vectors
Lyapunov exponents are well-known characteristic numbers that describe growth
rates of perturbations applied to a trajectory of a dynamical system in
different state space directions. Covariant (or characteristic) Lyapunov
vectors indicate these directions. Though the concept of these vectors has been
known for a long time, they became practically computable only recently due to
algorithms suggested by Ginelli et al. [Phys. Rev. Lett. 99, 2007, 130601] and
by Wolfe and Samelson [Tellus 59A, 2007, 355]. In view of the great interest in
covariant Lyapunov vectors and their wide range of potential applications, in
this article we summarize the available information related to Lyapunov vectors
and provide a detailed explanation of both the theoretical basics and numerical
algorithms. We introduce the notion of adjoint covariant Lyapunov vectors. The
angles between these vectors and the original covariant vectors are
norm-independent and can be considered as characteristic numbers. Moreover, we
present and study in detail an improved approach for computing covariant
Lyapunov vectors. Also we describe, how one can test for hyperbolicity of
chaotic dynamics without explicitly computing covariant vectors.Comment: 21 pages, 5 figure
Determination of the primordial helium abundance from radio recombination line observations: New data. The source W51
Observations of H and He radio recombination lines in the source W51 have been performed with the RT-22 radio telescope (Pushchino) in two transitions: 56α (8 mm) and 65α (13 mm). We have estimated the spectral line parameters and determined the relative abundance of ionized helium, y + = (9.3 ± 0.35)%. We have carried out a model study of the correction (R) for the ionization structure of HII regions (when passing from the observed y + = N(He+)/N(H+) to the actual y = N(He)/N(H)) as a function of the spectral type of the ionizing star. Hence it follows that it is desirable to choose the sources excited by hot stars of spectral types no later than O6 V to estimate the helium abundance. In this case, the correction is expected to be small and essentially constant, R in the range 1.0-1.05. We have analyzed the correction for the ionization structure of W51, obtained an actual abundance of helium in the range y = (8.9-9.7)%, and determined its primordial abundance Y p (produced during primordial nucleosynthesis in the Universe) in this source. We have made a new estimate of the primordial helium abundance from six Galactic HII regions, where we observed H and He radio recombination lines at different times. The weighted mean Y p = 25.64(±0.70)% has been obtained. On the one hand, this value of Y p does not yet disagree strongly with the conclusions of the standard cosmologicalmodel, but, on the other hand, it admits the existence of at least one unknown light particle in the period of primordial nucleosynthesis outside the scope of the standard cosmological model. One should continue to refine Y p for more reliable conclusions to be reached. © 2013 Pleiades Publishing, Inc
Halo Excitation of He in Inelastic and Charge-Exchange Reactions
Four-body distorted wave theory appropriate for nucleon-nucleus reactions
leading to 3-body continuum excitations of two-neutron Borromean halo nuclei is
developed. The peculiarities of the halo bound state and 3-body continuum are
fully taken into account by using the method of hyperspherical harmonics. The
procedure is applied for A=6 test-bench nuclei; thus we report detailed studies
of inclusive cross sections for inelastic He(p,p')He and
charge-exchange Li(n,p)He reactions at nucleon energy 50 MeV. The
theoretical low-energy spectra exhibit two resonance-like structures. The first
(narrow) is the excitation of the well-known three-body resonance. The
second (broad) bump is a composition of overlapping soft modes of
multipolarities whose relative weights depend on
transferred momentum and reaction type. Inelastic scattering is the most
selective tool for studying the soft dipole excitation mode.Comment: Submitted to Phys. Rev. C., 11 figures using eps
Relative luminosity measurement of the LHC with the ATLAS forward calorimeter
In this paper it is shown that a measurement of the relative luminosity
changes at the LHC may be obtained by analysing the currents drawn from the
high voltage power supplies of the electromagnetic section of the forward
calorimeter of the ATLAS detector. The method was verified with a reproduction
of a small section of the ATLAS forward calorimeter using proton beams of known
beam energies and variable intensities at the U-70 accelerator at IHEP in
Protvino, Russia. The experimental setup and the data taking during a test beam
run in April 2008 are described in detail. A comparison of the measured high
voltage currents with reference measurements from beam intensity monitors shows
a linear dependence on the beam intensity. The non-linearities are measured to
be less than 0.5 % combining statistical and systematic uncertainties.Comment: 16 page
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