Abstract (EN)

This Note presents two remarks on the notion of generalized flow solution to ordinary differential equations, as introduced by DiPerna and the third author (R.J. Di Perna, P.L. Lions, Ordinary differential equations, transport theory and Sobolev spaces, Invent. Math. 98 (3) (1989) 511–547). On the one hand, we provide a self-contained proof of the uniqueness of such a flow. By this, we mean that our new proof does not exploit the interpretation of the generalized flow in terms of flow for the associated linear transport equation. On the other hand, this time using the associated linear transport equation, we slightly extend the result of uniqueness contained in the article cited, proving it holds without the group property of the flow (in the time variable). To cite this article: M. Hauray et al., C. R. Acad. Sci. Paris, Ser. I 344 (2007).