English

Continuous spectrum or measurable reducibility for quasiperiodic cocycles in $\mathbb{T} ^{d} \times SU(2)$

Dynamical Systems 2018-01-29 v1

Abstract

We continue our study of the local theory for quasiperiodic cocycles in Td×G\mathbb{T} ^{d} \times G, where G=SU(2)G=SU(2), over a rotation satisfying a Diophantine condition and satisfying a closeness-to-constants condition, by proving a dichotomy between measurable reducibility (and therefore pure point spectrum), and purely continuous spectrum in the space orthogonal to L2(Td)L2(Td×G)L^{2}(\mathbb{T} ^{d}) \hookrightarrow L^{2}(\mathbb{T} ^{d} \times G). Subsequently, we describe the equivalence classes of cocycles under smooth conjugacy, as a function of the parameters defining their K.A.M. normal form. Finally, we derive a complete classification of the dynamics of one-frequency (d=1d=1) cocycles over a Recurrent Diophantine rotation. All theorems will be stated sharply in terms of the number of frequencies dd, but in the proofs we will always assume d=1d=1, for simplicity in expression and notation.

Keywords

Cite

@article{arxiv.1512.00057,
  title  = {Continuous spectrum or measurable reducibility for quasiperiodic cocycles in $\mathbb{T} ^{d} \times SU(2)$},
  author = {Nikolaos Karaliolios},
  journal= {arXiv preprint arXiv:1512.00057},
  year   = {2018}
}

Comments

25 pages, 1 figure. arXiv admin note: text overlap with arXiv:1407.4763