Abstract We prove a Nekhoroshev type theorem for the nonlinear Schrödinger equation iut = −∆u+ V ⋆ u+ ∂ūg(u, ū) , x ∈ T, where V is a typical smooth potential and g is analytic in both variables. More precisely we prove that if the initial datum is analytic in a strip of width ρ > 0 with a bound on this strip equals to ε then, if ε is small enough, the solution of the nonlinear Schrödinger equa...

We investigate the possibility to draw conclusions on the sign of the spindependent gluon distribution, ∆G(x,Q), from existing polarized DIS data. The spin-dependent parton distributions ∆uv,∆dv ,∆ū,∆d̄,∆s, and ∆G are constructed in the framework of a phenomenological procedure taking into account some assumptions on signs of valence and sea parton distributions motivated by ’t Hooft’s mechanism...

We report on recent work concerning the effect which the change in vacuum structure (negative energy Dirac sea), in the presence of a confining scalar field, has on the nucleon structure functions and parton distributions. Using the Dirac equation in 1+1 dimensions, we show that distortions in the Dirac sea are responsible for part of the violation of the Gottfried sum rule – i.e., part of the ...

A shallow-layer model for granular flows is completed with a closure relation for the macroscopic bed friction or basal roughness obtained from micro-scale discrete particle simulations of steady flows. We systematically vary the bed friction by changing the contact friction coefficient between basal and flowing particles, while the base remains geometrically rough. By simulating steady uniform...

We consider stability of an infinite dimensional switching system, posed as a system of linear hyperbolic partial differential equations (PDEs) with reflecting boundaries, where the system parameters and the boundary conditions switch in time. Asymptotic stability of the solution for arbitrary switching is proved under commutativity of the advective velocity matrices and a joint spectral radius...

The combined analysis of polarized DIS and SIDIS data is performed in NLO QCD. The new parametrization on polarized PDFs is constructed. The uncertainties on PDFs and their first moments are estimated applying the modified Hessian method. The especial attention is paid to the impact of novel SIDIS data on the polarized distributions of light sea and strange quarks. In particular, the important ...

We use a combination of classical Monte Carlo and spin dynamics simulations for the 2D classical easy-plane ferromagnet to estimate the lifetime of free vortices near the Kosterlitz-Thouless transition temperature. Using thermal equilibrium initial states from Monte Carlo, the spin equations of motion are integrated numerically and the number fluctuations of free vortices are used to calculate ...

We discuss two topics in this talk. One is a brief overview of nuclear parton distributions, and the other is SU(2)-flavor-symmetry breaking in nuclear antiquark distributions. First, we show that nuclear structure functions F 2 (x) could be explained in a Q rescaling model with parton recombination effects. Then, nuclear gluon distributions are discussed in this parton model. We point out othe...

We establish new results for the radial nonlinear wave and Schrödinger equations on the ball in R and R, for random initial data. More precisely, a well-defined and unique dynamics is obtained on the support of the corresponding Gibbs measure. This complements results from [6, 7] and [8, 9]. Résumé. On démontre des résultats nouveaux sur les équations des ondes et l’équation de Schrödinger radi...