3,639 research outputs found
The Vlasov equation and the Hamiltonian Mean-Field model
We show that the quasi-stationary states observed in the -particle
dynamics of the Hamiltonian Mean-Field (HMF) model are nothing but Vlasov
stable homogeneous (zero magnetization) states. There is an infinity of Vlasov
stable homogeneous states corresponding to different initial momentum
distributions. Tsallis -exponentials in momentum, homogeneous in angle,
distribution functions are possible, however, they are not special in any
respect, among an infinity of others. All Vlasov stable homogeneous states lose
their stability because of finite effects and, after a relaxation time
diverging with a power-law of the number of particles, the system converges to
the Boltzmann-Gibbs equilibrium
Transport through a molecular quantum dot in the polaron crossover regime
We consider resonant transport through a molecular quantum dot coupled to a
local vibration mode. Applying the non-equilibrium Green function technique in
the polaron representation, we develop a non-perturbative scheme to calculate
the electron spectral function of the molecule in the regime of intermediate
electron-phonon coupling. With increasing tunneling coupling to the leads,
correlations between polaron clouds become more important at relatively high
temperature leading to a strong sharpening of the peak structure in the
spectral function. The detection of such features in the current-voltage
characteristics is briefly discussed
Diagrammatic Approach for the High-Temperature Regime of Quantum Hall Transitions
We use a general diagrammatic formalism based on a local conductivity
approach to compute electronic transport in continuous media with long-range
disorder, in the absence of quantum interference effects. The method allows us
then to investigate the interplay of dissipative processes and random drifting
of electronic trajectories in the high-temperature regime of quantum Hall
transitions. We obtain that the longitudinal conductance \sigma_{xx} scales
with an exponent {\kappa}=0.767\pm0.002 in agreement with the value
{\kappa}=10/13 conjectured from analogies to classical percolation. We also
derive a microscopic expression for the temperature-dependent peak value of
\sigma_{xx}, useful to extract {\kappa} from experiments.Comment: 4+epsilon pages, 5 figures, attached with Supplementary Material. A
discussion and a plot of the temperature-dependent longitudinal conductance
was added in the final versio
Prediction of anomalous diffusion and algebraic relaxations for long-range interacting systems, using classical statistical mechanics
We explain the ubiquity and extremely slow evolution of non gaussian
out-of-equilibrium distributions for the Hamiltonian Mean-Field model, by means
of traditional kinetic theory. Deriving the Fokker-Planck equation for a test
particle, one also unambiguously explains and predicts striking slow algebraic
relaxation of the momenta autocorrelation, previously found in numerical
simulations. Finally, angular anomalous diffusion are predicted for a large
class of initial distributions. Non Extensive Statistical Mechanics is shown to
be unnecessary for the interpretation of these phenomena
Interest as Damages
In this article, we posit that when arbitral tribunals decide international disputes, they typically fail to fully compensate claimants for the loss of the use of their money. This failure occurs because they do not acknowledge that businesses typically invest in opportunities that pose a significantly greater risk than the risk reflected in such commonly used standards as U.S. T-bills and LIBOR rates. Claimants also must share the blame when they do not set out a well-constructed claim for interest as damages. However, even when claimants do so, tribunals often award damages at a statutory rate or at rate reflecting a nearly risk-free investment because they are unfamiliar with modern economic and financial principles. We propose changing this practice. We set out a legal framework for allowing an award of interest as damages and then furnish a model for claimants and tribunals to use. Under this model, interest accrues at a risk-free interest rate plus a market risk premium with the interest award to be compounded on a yearly basis. This model would bring awards in line with modern economic realities and more accurately compensate injured parties
Testing for Stochastic Dominance Efficiency
We propose a new test of the stochastic dominance efficiency of a given portfolio over a class
of portfolios. We establish its null and alternative asymptotic properties, and define a method
for consistently estimating critical values. We present some numerical evidence that our tests
work well in moderate sized samples
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