21–23 mai 2018
Faculté de Mathématique et Informatique de l'Université Bucarest
Fuseau horaire Europe/Bucharest

Comportement asymptotique des équations de convection-diffusion fractionnaires / Asymptotic behaviour for fractional diffusion-convection equations

21 mai 2018, 10:00
1h

Orateur

Liviu Ignat (IMAR, Bucarest, Roumanie)

Description

In this talk, we analyze the long time behaviour of the solutions of the equation $ u_t(t,x)+(-\Delta) ^{\alpha/2}u(t,x)+(f(u))_x=0,\ t\in (0,\infty),\ x\in\mathbf{R},$ where $\alpha\in (0,2)$ and $f(s)=|s|^{q-1}s/q$ with $q\in (1,\infty)$. We present some prvious results on the asymptotic expansion of the solutions when the time goes to infinity. We prove that in the one-dimensional case, for $q\in (1,\alpha)$ the asymptotic behaviour is given by the entropy solution of the conservation law $u_t(t,x)+(f(u))_x=0$, $u(0)=M\delta_0$ where $M$ is the mass of the initial data. The proof relies on tricky inequalities to guarantee an Oleinik type inequality $(u^{q-1})_x\leq 1/t$. This is a joint work with Diana Stan. This presentation is partially supported by CNCS-UEFISCDI No. PN-III-P4- ID-PCE-2016-0035.

Auteur principal

Liviu Ignat (IMAR, Bucarest, Roumanie)

Co-auteur

Diana Stan (Basque Center for Applied Mathematics, Bilabao, Espagne)

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