Formation of singularities for viscosity solutions of Hamilton-Jacobi equations
Formation of Singularities for Weakly Non-Linear N×N Hyperbolic Systems
We present some results on the formation of singularities for C^1 - solutions of the quasi-linear N × N strictly hyperbolic system Ut + A(U )Ux = 0 in [0, +∞) × Rx . Under certain weak non-linearity conditions (weaker than genuine non-linearity), we prove that the first order derivative of the solution blows-up in finite time.
Formes bilinéaires compatibles avec un système hyperbolique et problème de Cauchy
Forms, functional calculus, cosine functions and perturbation
In this article we describe properties of unbounded operators related to evolutionary problems. It is a survey article which also contains several new results. For instance we give a characterization of cosine functions in terms of mild well-posedness of the Cauchy problem of order 2, and we show that the property of having a bounded -calculus is stable under rank-1 perturbations whereas the property of being associated with a closed form and the property of generating a cosine function are not....
Formulation forte entropique de lois scalaires hyperboliques-paraboliques dégénérées
Formules de trace, résonances et quasi-modes
Fourier analysis of null forms and nonlinear wave equations.
Fourier integral operators and nonlinear wave equations
Fourier transform, oscillatory multipliers and evolution equations in rearrangement invariant function spaces
Free decay of solutions to wave equations on a curved background
We investigate for which metric (close to the standard metric ) the solutions of the corresponding d’Alembertian behave like free solutions of the standard wave equation. We give rather weak (i.e., non integrable) decay conditions on ; in particular, decays like along wave cones.
Free vibrations for the equation of a rectangular thin plate
In the paper, we deal with the equation of a rectangular thin plate with a simply supported boundary. The restoring force being an odd superlinear function of the vertical displacement, the existence of infinitely many nonzero time-periodic solutions is proved.
Front d'onde des fonctions non linéaires et polynômes
Fully adaptive multiresolution schemes for strongly degenerate parabolic equations in one space dimension
We present a fully adaptive multiresolution scheme for spatially one-dimensional quasilinear strongly degenerate parabolic equations with zero-flux and periodic boundary conditions. The numerical scheme is based on a finite volume discretization using the Engquist-Osher numerical flux and explicit time stepping. An adaptive multiresolution scheme based on cell averages is then used to speed up the CPU time and the memory requirements of the underlying finite volume scheme, whose first-order...
Functions of finite fractional variation and their applications to fractional impulsive equations
We introduce a notion of a function of finite fractional variation and characterize such functions together with their weak -additive fractional derivatives. Next, we use these functions to study differential equations of fractional order, containing a -additive term—we prove existence and uniqueness of a solution as well as derive a Cauchy formula for the solution. We apply these results to impulsive equations, i.e. equations containing the Dirac measures.
Fundamental solution of the operator for n>3
Fundamental solutions and singular shocks in scalar conservation laws.
We study the existence and non-existence of fundamental solutions for the scalar conservation laws ut + f(u)x = 0, related to convexity assumptions on f. We also study the limits of those solutions as the initial mass goes to infinity. We especially prove the existence of so-called Friendly Giants and Infinite Shock Solutions according to the convexity of f, which generalize the explicit power case f(u) = um. We introduce an extended notion of solution and entropy criterion to allow infinite shocks...