Reducibility of 1-D quantum harmonic oscillator with new unbounded oscillatory perturbations

Abstract

Enlightened by Lemma 1.7 in \cite{LiangLuo2021}, we prove a similar lemma which is based upon oscillatory integrals and Langer's turning point theory. From it we show that the Schr{\"o}dinger equation $${\rm i}\partial_t u = -\partial_x^2 u+x^2 u+\epsilon \langle x\rangle^\mu\sum_{k\in\Lambda}\left(a_k(\omega t)\sin(k|x|^\beta)+b_k(\omega t) \cos(k|x|^\beta)\right) u,\quad u=u(t,x),~x\in\mathbb{R},~ \beta>1,$$ can be reduced in $\mathcal{H}^1(\mathbb{R})$ to an autonomous system for most values of the frequency vector $\omega$, where $\Lambda\subset\mathbb R\setminus\{0\}$, $|\Lambda|<\infty$ and $\langle x\rangle:=\sqrt{1+x^2}$. The functions $a_k(\theta)$ and $b_k(\theta)$ are analytic on $\mathbb T^n_\sigma$ and $\mu\geq 0$ will be chosen according to the value of $\beta$. Comparing with \cite{LiangLuo2021}, the novelty is that the phase functions of oscillatory integral are more degenerate when $\beta>1$.