Propagation and cancellation of singularities in a class of Fuchsian operators and their perturbations.
Propagation de la régularité locale de solutions d'équations hyperboliques non linéaires
Pour tout réel positif , on étudie la propagation de la régularité locale pour des solutions d’équations aux dérivées partielles hyperboliques non linéaires, admettant a priori la régularité minimale permettant de définir les expressions non linéaires figurant dans l’équation. En particulier, on démontre le théorème de propagation dans le cas des solutions essentiellement bornées (resp. lipschitziennes) de systèmes du premier ordre semi-linéaires (resp. quasi-linéaires).
Propagation de l'analyticité des solutions de systèmes hyperboliques non-linéaires.
Propagation of analyticity of the solutions to the Cauchy problem for nonlinear symmetrizable systems
Propagation of weak discontinuities for quasilinear hyperbolic systems with coefficients functionally dependent on solutions
The propagation of weak discontinuities for quasilinear systems with coefficients functionally dependent on the solution is studied. We demonstrate that, similarly to the case of usual quasilinear systems, the transport equation for the intensity of weak discontinuity is quadratic in this intensity. However, the contribution from the (nonlocal) functional dependence appears to be in principle linear in the jump intensity (with some exceptions). For illustration, several examples, including two hyperbolic...
Qualitative properties of a certain kinetic model of a binary gas.
Quasilinear hyperbolic 2 x 2 systems with a free, damping boundary condition.
Quasi-symmetrization of hyperbolic systems and propagation of the analytic regularity
Dopo aver introdotto la nozione di quasi-simmetrizzatore per sistemi del prim'ordine debolmente iperbolici, si dimostra che ad ogni sistema di tipo Sylvester, cioè proveniente da un'equazione scalare di ordine superiore, si può associare in modo regolare un quasi-simmetrizzatore. Come applicazione di questo risultato si prova che, per qualunque sistema semi-lineare debolmente iperbolico, le soluzioni Gevrey in x di ordine restano analitiche non appena lo siano all'istante iniziale.
Quelques méthodes d'étude de la propagation d'oscillations hyperboliques non linéaires
Regular Solutions of Initial-Boundary Value Problems for Linear and Nonlinear Wave - Equations I.
Regular Solutions of Initial-Boundary Value-Problems for Linear and Nonlinear Wave-Equations. II.
Régularité conormale classique des problèmes de Cauchy et de réflexion transverse pour un système semi-linéaire
On considère un système semi-linéaire du premier ordre de taille dans un ouvert de , une hypersurface non caractéristique et une hypersurface de . On suppose que, par , passent deux hypersurfaces caractéristiques , transverses et que les bicaractéristiqiues sur , sont transverses à . Soit une solution dans une demi-région délimitée par . On suppose que est la restriction à d’une distribution conormale par morceaux par rapport à , . Pour le problème de Cauchy, on montre...
Relaxation and numerical approximation of a two-fluid two-pressure diphasic model
This paper is concerned with the numerical approximation of the solutions of a two-fluid two-pressure model used in the modelling of two-phase flows. We present a relaxation strategy for easily dealing with both the nonlinearities associated with the pressure laws and the nonconservative terms that are inherently present in the set of convective equations and that couple the two phases. In particular, the proposed approximate Riemann solver is given by explicit formulas, preserves the natural...
Renormalized entropy solutions of scalar conservation laws
Semilinear Hyperbolic Systems and Equations with Singular Initial Data.
Semilinear hyperbolic systems in one space dimension with strongly singular initial data.
Singular Convergence of Weak Solutions for a Quasilinear Nonhomogeneous.
Singular Perturbations for a Class of Degenerate Parabolic Equations with Mixed Dirichlet-Neumann Boundary Conditions
We establish a singular perturbation property for a class of quasilinear parabolic degenerate equations associated with a mixed Dirichlet-Neumann boundary condition in a bounded domain of , . In order to prove the -convergence of viscous solutions toward the entropy solution of the corresponding first-order hyperbolic problem, we refer to some properties of bounded sequences in together with a weak formulation of boundary conditions for scalar conservation laws.
Singularités des solutions d'équations d'ondes semi-linéaires
Small analytic solutions to nonlinear weakly hyperbolic systems