Date of Award

Spring 2022

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mathematics

First Advisor

Schlag, Wilhelm

Abstract

This dissertation addresses the question of Anderson localization for quasi-periodic discrete Schr\"odinger operators $H = \varepsilon\Delta + V$ with potential $V$ sampled with Diophantine frequency $\alpha$ from an asymmetric, smooth, cosine-like function $v \in C^2(\mathbb{T},[-1,1])$. After reviewing the known results in case $v$ is analytic or symmetric, we develop an inductive analysis on scales, whereby we show that locally the Rellich functions of Dirichlet restrictions of $H$ inherit the cosine-like structure of $v$ and are uniformly well-separated. We utilize this construction to prove almost-sure Anderson localization and Cantor spectrum in our case for sufficiently small interaction $\varepsilon \leq \varepsilon_0(v,\alpha)$.

COinS