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Calcul exponentiel des opérateurs microdifférentiels d'ordre infini. II

Takashi Aoki (1986)

Annales de l'institut Fourier

Soit P un opérateur pseudodifférentiel (ou microdifférentiel) tel que exp P soit aussi un opérateur pseudodifférentiel. Alors le symbole de exp P s’ecrit exp q avec un symbole q . Pour la réciproque, si Q est un opérateur à symbole exp q , il existe un opérateur P tel que Q = exp P . Tous ces résultats reposent sur la théorie développée dans la Note I de cette série. Comme application, on obtient une condition suffisante d’inversibilité pour les opérateurs pseudodifférentiels d’ordre infini.

Calcul exponentiel des opérateurs microdifférentiels d'ordre infini. I

Takashi Aoki (1983)

Annales de l'institut Fourier

Cet article s’intéresse au calcul symbolique des opérateurs microdifférentiels avec symboles exponentiels. On donne la loi de composition des symboles exponentiels. Comme application, on trouve une condition suffisante d’ellipticité pour les opérateurs microdifférentiels d’ordre infini.

Cascade of phases in turbulent flows

Christophe Cheverry (2006)

Bulletin de la Société Mathématique de France

This article is devoted to incompressible Euler equations (or to Navier-Stokes equations in the vanishing viscosity limit). It describes the propagation of quasi-singularities. The underlying phenomena are consistent with the notion of a cascade of energy.

Cauchy problem for a class of parabolic systems of Shilov type with variable coefficients

Vladyslav Litovchenko, Iryna Dovzhytska (2012)

Open Mathematics

In the case of initial data belonging to a wide class of functions including distributions of Gelfand-Shilov type we establish the correct solvability of the Cauchy problem for a new class of Shilov parabolic systems of equations with partial derivatives with bounded smooth variable lower coefficients and nonnegative genus. We also investigate the conditions of local improvement of the convergence of a solution of this problem to its limiting value when the time variable tends to zero.

Cauchy problem for the complex Ginzburg-Landau type Equation with L p -initial data

Daisuke Shimotsuma, Tomomi Yokota, Kentarou Yoshii (2014)

Mathematica Bohemica

This paper gives the local existence of mild solutions to the Cauchy problem for the complex Ginzburg-Landau type equation u t - ( λ + i α ) Δ u + ( κ + i β ) | u | q - 1 u - γ u = 0 in N × ( 0 , ) with L p -initial data u 0 in the subcritical case ( 1 q < 1 + 2 p / N ), where u is a complex-valued unknown function, α , β , γ , κ , λ > 0 , p > 1 , i = - 1 and N . The proof is based on the L p - L q estimates of the linear semigroup { exp ( t ( λ + i α ) Δ ) } and usual fixed-point argument.

Certified reduced-basis solutions of viscous Burgers equation parametrized by initial and boundary values

Alexandre Janon, Maëlle Nodet, Clémentine Prieur (2013)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

We present a reduced basis offline/online procedure for viscous Burgers initial boundary value problem, enabling efficient approximate computation of the solutions of this equation for parametrized viscosity and initial and boundary value data. This procedure comes with a fast-evaluated rigorous error bound certifying the approximation procedure. Our numerical experiments show significant computational savings, as well as efficiency of the error bound.

Classification of Monge-Ampère equations with two variables

Boris Kruglikov (1999)

Banach Center Publications

This paper deals with the classification of hyperbolic Monge-Ampère equations on a two-dimensional manifold. We solve the local equivalence problem with respect to the contact transformation group assuming that the equation is of general position nondegenerate type. As an application we formulate a new method of finding symmetries. This together with previous author's results allows to state the solution of the classical S. Lie equivalence problem for the Monge-Ampère equations.

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