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Valentin Lemarié

Publications and source records attributed to Valentin Lemarié.

4 recordsLinked to original sources

The Pressureless Euler--Navier--Stokes System

In this paper, we study the well-posedness of the pressureless Euler-Navier-Stokes system in $\R^d$ (with $d\geq 2$) in the critical regularity setting for a density close to $0$. We prove a global existence result for small data for this system, and then give optimal time decay estimates.

math.AP

The primitive equations for the ocean and atmosphere in anisotropic spaces

In this work, we study the well-posedness of the primitive equations for the ocean and the atmosphere on two specific domains: a bounded domain $Ω_1\mathrel{\mathop:}=(-1,1)^3$ with periodic boundary conditions, and the strip $Ω_2\mathrel{\mathop:}=\mathbb{R}^2\times(-1,1)$ with periodic boundary conditions in the vertical direction. In a first time, we establish a global existence and uniqueness theorem for small initial data in a suitable anisotropic Besov space. Then, we also justify, in a similar functional framework, the singular limit from the anisotropic Navier-Stokes equations to this system.

math.AP

From anisotropic Navier-Stokes equations to primitive equations for the ocean and atmosphere

We study the well-posedness of the primitive equations for the ocean and atmosphere on two particular domains : a bounded domain $Ω_1 := (-1, 1)^3$ with periodic boundary conditions and the strip $Ω_2 := \mathbb{R}^2 \times (-1, 1)$ with a periodic boundary condition for the vertical coordinate. An existence theorem for global solutions on a suitable Besov space is derived. Then, in a second step, we rigorously justify the passage to the limit from the rescaled anisotropic Navier-Stokes equations to these primitive equations in the same functional framework as that found for the solutions of the primitive equations.

math.AP

Parabolic-elliptic Keller-Segel's system

We study on the whole space R d the compressible Euler system with damping coupled to the Poisson equation when the damping coefficient tends towards infinity. We first prove a result of global existence for the Euler-Poisson system in the case where the damping is large enough, then, in a second step, we rigorously justify the passage to the limit to the parabolic-elliptic Keller-Segel after performing a diffusive rescaling, and get an explicit convergence rate. The overall study is carried out in 'critical' Besov spaces, in the spirit of the recent survey [16] by R. Danchin devoted to partially dissipative systems.

math.AP