Hokkaido University Preprint Series in Mathematics
The Cauchy problem for a coupled system of Schr\"odinger and improved Boussinesq equations is studied. Local well-posedness is proved in $L^2(\R^n)$ for $n\le 3$. Global well-posedness is proved in the energy space for $n\le 2$. Under smallness assumption on the Cauchy data, the local result in $L^2$ is proved for $n=4$.