%0 Journal Article %T Well-posedness and stability in the periodic case for the Benney system %A J. Angulo %A A. J. Corcho %A And S. Hakkaev %J Mathematics %D 2010 %I arXiv %X We establish local well-posedness results in weak periodic function spaces for the Cauchy problem of the Benney system. The Sobolev space $H^{1/2}\times L^2$ is the lowest regularity attained and also we cover the energy space $H^{1}\times L^2$, where global well-posedness follows from the conservation laws of the system. Moreover, we show the existence of smooth explicit family of periodic travelling waves of \emph{dnoidal} type and we prove, under certain conditions, that this family is orbitally stable in the energy space. %U http://arxiv.org/abs/1009.0944v2