On the spectrum of the Schrödinger operator on ${\mathbb{T}}^d$: a normal form approach

Dario Bambusi, Beatrice Langella, Riccardo Montalto

In this paper we study the spectrum of the operator \begin{equation} \label{ope} H:=(-Δ)^{M/2}+\mathcal{V}\ , \quad M>0\ , \end{equation} on $L^2({\mathbb{R}}^d/\Gamma )$, with $\Gamma$ a maxim…