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arXiv · 0910.4991

On a maximum principle and its application to logarithmically critical Boussinesq system

Taoufik Hmidi
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Abstract

In this paper we study a transport-diffusion model with some logarithmic dissipations. We look for two kinds of estimates. The first one is a maximum principle whose proof is based on Askey theorem concerning characteristic functions and some tools from the theory of $C_0$-semigroups. The second one is a smoothing effect based on some results from harmonic analysis and sub-Markovian operators. As an application we prove the global well-posedness for the two-dimensional Euler-Boussinesq system where the dissipation occurs only on the temperature equation and has the form $\frac{\DD}{\log^α(e^4+\DD)}$, with $α\in[0,\frac12]$. This result improves the critical dissipation $(α=0)$ needed for global well-posedness which was discussed in [15].

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Taoufik Hmidi. 2009-11-07. On a maximum principle and its application to logarithmically critical Boussinesq system. https://arxiv.org/abs/0910.4991

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