The absolutely continuous spectrum of the almost Mathieu operator

2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/171669We prove that the spectrum of the almost Mathieu operator is absolutely continuous if and only if the coupling is subcritical. This settles Problem 6 of Barry Simon's list of Schrödinger operator problems for the twenty-first century.22 pagesDynamical SystemsMathematical PhysicsSpectral TheoryThe absolutely continuous spectrum of the almost Mathieu operatortext