Growth of Sobolev norms for abstract linear Schrödinger equations

Abstract

We prove an abstract theorem giving a $⟨t{⟩}^{ϵ}$ bound (for all $ϵ>0$) on the growth of the Sobolev norms in linear Schrödinger equations of the form $\mathrm{i}\dot{\psi }=H_0\psi +V(t)\psi$ as $t\to \infty$. The abstract theorem is applied to several cases, including the cases where (i) $H_0$ is the Laplace operator on a Zoll manifold and $V(t)$ a pseudodifferential operator of order smaller than 2; (ii) $H_0$ is the (resonant or nonresonant) Harmonic oscillator in $mathbb{\mathbb{R}}^d$ and $V(t)$ a pseudodifferential operator of order smaller than that of $H_0$ depending in a quasiperiodic way on time. The proof is obtained by first conjugating the system to some normal form in which the perturbation is a smoothing operator and then applying the results of [MR17].