Complex one-frequency cocycles
Artur AvilaUniversité Pierre et Marie Curie, Paris, France
Svetlana JitomirskayaUniversity of California, Irvine, United States
Christian SadelPontificia Universidad Católica de Chile, Santiago de Chile, Chile
We show that on a dense open set of analytic one-frequency complex valued cocycles in arbitrary dimension Oseledets filtration is either dominated or trivial. The underlying mechanism is different from that of the Bochi-Viana Theorem for continuous cocycles, which links non-domination with discontinuity of the Lyapunov exponent. Indeed, in our setting the Lyapunov exponents are shown to depend continuously on the cocycle, even if the initial irrational frequency is allowed to vary. On the other hand, this last property provides a good control of the periodic approximations of a cocycle, allowing us to show that domination can be characterized, in the presence of a gap in the Lyapunov spectrum, by additional regularity of the dependence of sums of Lyapunov exponents.
Cite this article
Artur Avila, Svetlana Jitomirskaya, Christian Sadel, Complex one-frequency cocycles. J. Eur. Math. Soc. 16 (2014), no. 9, pp. 1915–1935DOI 10.4171/JEMS/479