On the flow map of the Benjamin-Ono equation on the torus

Patrick Gerard; Thomas Kappeler; Peter Topalov

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arXiv · 1909.07314

On the flow map of the Benjamin-Ono equation on the torus

Patrick Gerard·Thomas Kappeler·Peter Topalov

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Abstract

We prove that for any $0 < s < 1/2$, the Benjamin--Ono equation on the torus is globally in time $C^0-$well-posed on the Sobolev space $H^{-s}(\T, \R)$,in the sense that the solution map, which is known to be defined for smooth data, continuously extends to $H^{-s}(\T,\R)$. The solution map does not extend continuously to $H^{-s}(\T, \R)$ with $s > 1/2$. Hence the critical Sobolev exponent $s_c=-1/2$ of the Benjamin--Ono equation is the threshold for well-posedness on the torus. The obtained solutions are almost periodic in time. Furthermore, we prove that the traveling wave solutions of the Benjamin--Ono equation on the torus are orbitally stable in $H^{-s}(\T,\R)$ for any $0\le s<1/2$.

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Patrick Gerard, Thomas Kappeler, Peter Topalov. 2019-09-16. On the flow map of the Benjamin-Ono equation on the torus. https://arxiv.org/abs/1909.07314

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