On the Lyapunov exponent and exponential dichotomy for the quasi-periodic Schrödinger operator
In this paper we study the Lyapunov exponent for the one-dimensional Schrödinger operator with a quasi-periodic potential. Let be the set of frequency vectors whose components are rationally independent. Let , and consider the complement in of the set where exponential dichotomy holds. We show that is generic in this complement. The methods and techniques used are based on the concepts of rotation number and exponential dichotomy.