IUMJ

Title: Bounds on the growth of high Sobolev norms of solutions to nonlinear Schroedinger equations on $\mathbb{R}$

Authors: Vedran Sohinger

Issue: Volume 60 (2011), Issue 5, 1487-1516

Abstract:

In this paper, we consider the cubic nonlinear Schr\"odinger equation, and the Hartree equation, with sufficiently regular convolution potential, both on the real line. We are interested in bounding the growth of high Sobolev norms of solutions to these equations. Since the cubic NLS is completely integrable, it makes sense to bound only the fractional Sobolev norms of solutions whose initial data is of restricted smoothness. For the Hartree equation, we consider all Sobolev norms. For both equations, we derive our results by using an appropriate frequency decomposition. In the case of the cubic NLS, this method allows us to recover uniform bounds on the integral Sobolev norms, up to a factor of $t^{0+}$. For the Hartree equation, we use the same method as in our previous paper [V. Sohinger, \textit{Bounds on the growth of high Sobolev norms of solutions to nonlinear Schr\"odinger equations on $S^1$}, Differential Integral Equations \textbf{24} (2011), no. 7-8, 653--718] and the improved Strichartz estimate to obtain a better bound than the one that was obtained in the periodic setting in the mentioned work.