The null condition and global existence of nonlinear elsastic waves.
The propagation of singularities for pseudo-differential operators with self-tangential characteristics
The radiation field is a Fourier integral operator
We show that the ``radiation field'' introduced by F.G. Friedlander, mapping Cauchy data for the wave equation to the rescaled asymptotic behavior of the wave, is a Fourier integral operator on any non-trapping asymptotically hyperbolic or asymptotically conic manifold. The underlying canonical relation is associated to a ``sojourn time'' or ``Busemann function'' for geodesics. As a consequence we obtain some information about the high frequency behavior of the scattering...
The relationship between the local temperature and the local heat flux within a one-dimensional semi-infinite domain of heat wave propagation.
The second-order Klein-Gordon field equation.
The two-dimensional eikonal equation.
The uniform exponential stability and the uniform stability at constantly acting disturbances of a periodic solution of a wave equation
The wave equation with oscillating density : observability at low frequency
The wave equation with oscillating density : observability at low frequency
The wave equation with oscillating density: observability at low frequency
We prove an observability estimate for a wave equation with rapidly oscillating density, in a bounded domain with Dirichlet boundary condition.
The Wave Group and Radiation Fields on Asymptotically Hyperbolic Manifolds
The wave map problem. Small data critical regularity
The paper provides a description of the wave map problem with a specific focus on the breakthrough work of T. Tao which showed that a wave map, a dynamic lorentzian analog of a harmonic map, from Minkowski space into a sphere with smooth initial data and a small critical Sobolev norm exists globally in time and remains smooth. When the dimension of the base Minkowski space is , the critical norm coincides with energy, the only manifestly conserved quantity in this (lagrangian) theory. As a consequence,...
The well-posedness of the Dirichlet problem in the cylindric domain for the multidimensional wave equation.
Théorie de la diffusion pour l'équation de sinus-Gordon à trois dimensions
Théorie spectrale de la propagation des ondes acoustiques dans un milieu stratifié perturbe
Three-level difference schemes on non-uniform in time grids.
Time decay estimates for a perturbed wave equation
Time deformations of powers of the wave operator.
Time domain simulation of a piano. Part 1: model description
The purpose of this study is the time domain modeling of a piano. We aim at explaining the vibratory and acoustical behavior of the piano, by taking into account the main elements that contribute to sound production. The soundboard is modeled as a bidimensional thick, orthotropic, heterogeneous, frequency dependent damped plate, using Reissner Mindlin equations. The vibroacoustics equations allow the soundboard to radiate into the surrounding air, in which we wish to compute the complete acoustical...
Time splitting for wave equations in random media
Numerical simulation of high frequency waves in highly heterogeneous media is a challenging problem. Resolving the fine structure of the wave field typically requires extremely small time steps and spatial meshes. We show that capturing macroscopic quantities of the wave field, such as the wave energy density, is achievable with much coarser discretizations. We obtain such a result using a time splitting algorithm that solves separately and successively propagation and scattering in the simplified...