An ill posed Cauchy problem for a hyperbolic system in two space dimensions
An improved maximal inequality for 2D fractional order Schrödinger operators
The local maximal operator for the Schrödinger operators of order α > 1 is shown to be bounded from to L² for any s > 3/8. This improves the previous result of Sjölin on the regularity of solutions to fractional order Schrödinger equations. Our method is inspired by Bourgain’s argument in the case of α = 2. The extension from α = 2 to general α > 1 faces three essential obstacles: the lack of Lee’s reduction lemma, the absence of the algebraic structure of the symbol and the inapplicable...
An improved regularity criteria for the MHD system based on two components of the solution
As observed by Yamazaki, the third component of the magnetic field can be estimated by the corresponding component of the velocity field in
An initial boundary value problem for Maxwell's equations in a parabolic limit case.
An integral formula of hyperbolic type for solutions of the Dirac equation on Minkowski space with initial conditions on a hyperboloid
The Dirac equation for spinor-valued fields on the Minkowski space of even dimension form a hyperbolic system of partial differential equations. In the paper, we are showing how to reconstruct the solution from initial data given on the upper sheet of the hyperboloid. In particular, we derive an integral formula expressing the value of in a chosen point as an integral over a compact cycle given by the intersection of the null cone with in the Minkowski space .
An interacting particles process for Burgers equation on the circle.
An interpretation of the Vakulenko-Kapitanskiĭ estimate.
An introduction to probabilistic methods with applications
This special volume of the ESAIM Journal, Mathematical Modelling and Numerical Analysis, contains a collection of articles on probabilistic interpretations of some classes of nonlinear integro-differential equations. The selected contributions deal with a wide range of topics in applied probability theory and stochastic analysis, with applications in a variety of scientific disciplines, including physics, biology, fluid mechanics, molecular chemistry, financial mathematics and bayesian statistics....
An introduction to the Einstein-Vlasov system
An inverse problem for a nonlinear Schrödinger equation.
An inverse problem for time-harmonic electromagnetic currents in a smoothly layered medium.
An isoperimetric bound for a Sobolev constant
An -theory of the generalized Stokes resolvent system in infinite cylinders
Estimates of the generalized Stokes resolvent system, i.e. with prescribed divergence, in an infinite cylinder Ω = Σ × ℝ with , a bounded domain of class , are obtained in the space , q ∈ (1,∞). As a preparation, spectral decompositions of vector-valued homogeneous Sobolev spaces are studied. The main theorem is proved using the techniques of Schauder decompositions, operator-valued multiplier functions and R-boundedness of operator families.
An Optimal Control Problem for a Predator-Prey Reaction-Diffusion System
An optimal control problem is studied for a predator-prey system of PDE, with a logistic growth rate of the prey and a general functional response of the predator. The control function has two components. The purpose is to maximize a mean density of the two species in their habitat. The existence of the optimal solution is analyzed and some necessary optimality conditions are established. The form of the optimal control is found in some particular...
An unconditionally stable pressure correction scheme for the compressible barotropic Navier-Stokes equations
We present in this paper a pressure correction scheme for the barotropic compressible Navier-Stokes equations, which enjoys an unconditional stability property, in the sense that the energy and maximum-principle-based a priori estimates of the continuous problem also hold for the discrete solution. The stability proof is based on two independent results for general finite volume discretizations, both interesting for their own sake: the L2-stability of the discrete advection operator provided it...
An upper bound on the attractor dimension of a 2D turbulent shear flow with a free boundary condition
We consider a free boundary problem of a two-dimensional Navier-Stokes shear flow. There exist a unique global in time solution of the considered problem as well as the global attractor for the associated semigroup. As in [1] and [2], we estimate from above the dimension of the attractor in terms of given data and the geometry of the domain of the flow. This research is motivated by a free boundary problem from lubrication theory where the domain of the flow is usually very thin and the roughness...
Analycity of the Semigroup Generated by the Stokes Operator.
Analyse 2-microlocale et équations d'Euler incompressible
Analyse de sensibilité d’un problème de contrôle optimal bilinéaire
Dans cet article, nous étudions la sensibilité d’un problème de contrôle optimal de type bilinéaire. Le coût est différentiable, quadratique et strictement convexe. Le système est gouverné par un opérateur parabolique du quatrième ordre et présente une perturbation additive dans l’équation d’état, ainsi qu’une partie bilinéaire, relativement au contrôle et à l’état , de la forme . Sous des conditions de petitesse de l’état initial et de la perturbation, nous exploitons les propriétés de régularité...
Analyse d'un élément mixte pour le problème de Stokes . I. Résultats générauax.