157 research outputs found
Investigation of cosmic radiation on the AMS ''Luna-10''
Flux of primary cosmic radiation from Luna-1
Registration of Solar Cosmic Rays on the AMS ''luna-11''
Proton flux measurements onboard lunar prob
Registration of Electrons with Energies Greater than 30 Kev in the Near-lunar Space
Measured high energy electron flux in lunar environment by gas-discharge counter on lunar prob
Study of the soft corpuscular radiation on the AMS ''Luna-10''
Lunar-10 measurements of soft corpuscular radiatio
New Evidence of Discrete Scale Invariance in the Energy Dissipation of Three-Dimensional Turbulence: Correlation Approach and Direct Spectral Detection
We extend the analysis of [Zhou and Sornette, Physica D 165, 94-125, 2002]
showing statistically significant log-periodic corrections to scaling in the
moments of the energy dissipation rate in experiments at high Reynolds number
() of three-dimensional fully developed turbulence. First, we
develop a simple variant of the canonical averaging method using a rephasing
scheme between different samples based on pairwise correlations that confirms
Zhou and Sornette's previous results. The second analysis uses a simpler local
spectral approach and then performs averages over many local spectra. This
yields stronger evidence of the existence of underlying log-periodic
undulations, with the detection of more than 20 harmonics of a fundamental
logarithmic frequency corresponding to the preferred
scaling ratio .Comment: 9 RevTex4 papes including 8 eps figure
Adiabaticity Conditions for Volatility Smile in Black-Scholes Pricing Model
Our derivation of the distribution function for future returns is based on
the risk neutral approach which gives a functional dependence for the European
call (put) option price, C(K), given the strike price, K, and the distribution
function of the returns. We derive this distribution function using for C(K) a
Black-Scholes (BS) expression with volatility in the form of a volatility
smile. We show that this approach based on a volatility smile leads to relative
minima for the distribution function ("bad" probabilities) never observed in
real data and, in the worst cases, negative probabilities. We show that these
undesirable effects can be eliminated by requiring "adiabatic" conditions on
the volatility smile
Turbulence and Multiscaling in the Randomly Forced Navier Stokes Equation
We present an extensive pseudospectral study of the randomly forced
Navier-Stokes equation (RFNSE) stirred by a stochastic force with zero mean and
a variance , where is the wavevector and the dimension . We present the first evidence for multiscaling of velocity structure
functions in this model for . We extract the multiscaling exponent
ratios by using extended self similarity (ESS), examine their
dependence on , and show that, if , they are in agreement with those
obtained for the deterministically forced Navier-Stokes equation (NSE). We
also show that well-defined vortex filaments, which appear clearly in studies
of the NSE, are absent in the RFNSE.Comment: 4 pages (revtex), 6 figures (postscript
Developed turbulence: From full simulations to full mode reductions
Developed Navier-Stokes turbulence is simulated with varying wavevector mode
reductions. The flatness and the skewness of the velocity derivative depend on
the degree of mode reduction. They show a crossover towards the value of the
full numerical simulation when the viscous subrange starts to be resolved. The
intermittency corrections of the scaling exponents of the pth order velocity
structure functions seem to depend mainly on the proper resolution of the
inertial subrange. Universal scaling properties (i.e., independent of the
degree of mode reduction) are found for the relative scaling exponents rho
which were recently defined by Benzi et al.Comment: 4 pages, 5 eps-figures, replaces version from August 5th, 199
Dynamical Organization around Turbulent Bursts
The detailed dynamics around intermittency bursts is investigated in
turbulent shell models. We observe that the amplitude of the high wave number
velocity modes vanishes before each burst, meaning that the fixed point in zero
and not the Kolmogorov fixed point determines the intermittency. The phases of
the field organize during the burst, and after a burst the field oscillates
back to the laminar level. We explain this behavior from the variations in the
values of the dissipation and the advection around the zero fixed point.Comment: 4 pages, REVTex, 3 figures in one ps-fil
Time-reversible Dynamical Systems for Turbulence
Dynamical Ensemble Equivalence between hydrodynamic dissipative equations and
suitable time-reversible dynamical systems has been investigated in a class of
dynamical systems for turbulence. The reversible dynamics is obtained from the
original dissipative equations by imposing a global constraint. We find that,
by increasing the input energy, the system changes from an equilibrium state to
a non-equilibrium stationary state in which an energy cascade, with the same
statistical properties of the original system, is clearly detected.Comment: 16 pages Latex, 4 PS figures, on press on J. Phy
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