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A Nonperturbative Eliasson's Reducibility Theorem

Joaquim Puig
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Abstract

This paper is concerned with discrete, one-dimensional Schrödinger operators with real analytic potentials and one Diophantine frequency. Using localization and duality we show that almost every point in the spectrum admits a quasi-periodic Bloch wave if the potential is smaller than a certain constant which does not depend on the precise Diophantine conditions. The associated first-order system, a quasi-periodic skew-product, is shown to be reducible for almost all values of the energy. This is a partial nonperturbative generalization of a reducibility theorem by Eliasson. We also extend nonperturbatively the genericity of Cantor spectrum for these Schrödinger operators. Finally we prove that in our setting, Cantor spectrum implies the existence of a $G_δ$-set of energies whose Schrödinger cocycle is not reducible to constant coefficients.

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BibTeXRIS

Joaquim Puig. 2005-03-17. A Nonperturbative Eliasson's Reducibility Theorem. https://doi.org/10.1088/0951-7715%2F19%2F2%2F007

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