Cantor spectrum for Schrödinger operators with potentials arising from generalized skew-shifts
Avila, Artur ; Bochi, Jairo ; Damanik, David
Duke Math. J., Tome 146 (2009) no. 1, p. 253-280 / Harvested from Project Euclid
We consider continuous ${\rm SL}(2,\mathbb{R})$ -cocycles over a strictly ergodic homeomorphism that fibers over an almost periodic dynamical system (generalized skew-shifts). We prove that any cocycle that is not uniformly hyperbolic can be approximated by one that is conjugate to an $\rm{SO}(2,\mathbb{R})$ -cocycle. Using this, we show that if a cocycle's homotopy class does not display a certain obstruction to uniform hyperbolicity, then it can be $C^0$ -perturbed to become uniformly hyperbolic. For cocycles arising from Schrödinger operators, the obstruction vanishes, and we conclude that uniform hyperbolicity is dense, which implies that for a generic continuous potential, the spectrum of the corresponding Schrödinger operator is a Cantor set
Publié le : 2009-02-01
Classification:  37D,  47B36,  47B80,  81Q10
@article{1231170940,
     author = {Avila, Artur and Bochi, Jairo and Damanik, David},
     title = {Cantor spectrum for Schr\"odinger operators with potentials arising from generalized skew-shifts},
     journal = {Duke Math. J.},
     volume = {146},
     number = {1},
     year = {2009},
     pages = { 253-280},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1231170940}
}
Avila, Artur; Bochi, Jairo; Damanik, David. Cantor spectrum for Schrödinger operators with potentials arising from generalized skew-shifts. Duke Math. J., Tome 146 (2009) no. 1, pp.  253-280. http://gdmltest.u-ga.fr/item/1231170940/