English

Thresholds and more bands of a.c. Spectrum for the discrete Schr{\"o}dinger operator with a more general long range condition

Functional Analysis 2022-01-25 v1 Mathematical Physics math.MP Spectral Theory

Abstract

We continue the investigation of the existence of absolutely continuous (a.c.) spectrum for the discrete Schr\"odinger operator Δ+V\Delta+V on 2(Zd)\ell^2(\Z^d), in dimensions d2d\geq 2, for potentials VV satisfying the long range condition ni(VτiκV)(n)=O(lnq(n))n_i(V-\tau_i ^{\kappa}V)(n) = O(\ln^{-q}(|n|)) for some q>2q>2, κN\kappa \in \N, and all 1id1 \leq i \leq d, as n|n| \to \infty. τiκV\tau_i ^{\kappa} V is the potential shifted by κ\kappa units on the ithi^{\text{th}} coordinate. The difference between this article and \cite{GM2} is that here finite linear combinations of conjugate operators are constructed leading to more bands of a.c.\ spectrum being observed. The methodology is backed primarily by graphical evidence because the linear combinations are built by numerically implementing a polynomial interpolation. On the other hand an infinitely countable set of thresholds, whose exact definition is given later, is rigorously identified. Our overall conjecture, at least in dimension 2, is that the spectrum of Δ+V\Delta+V is void of singular continuous spectrum, and consecutive thresholds are endpoints of a band of a.c. spectrum.

Keywords

Cite

@article{arxiv.2201.09545,
  title  = {Thresholds and more bands of a.c. Spectrum for the discrete Schr{\"o}dinger operator with a more general long range condition},
  author = {Sylvain Golénia and Marc-Adrien Mandich},
  journal= {arXiv preprint arXiv:2201.09545},
  year   = {2022}
}

Comments

arXiv admin note: substantial text overlap with arXiv:2201.00410