Skip to main content
Log in

Hölder Continuity of the Rotation Number for Quasi-Periodic Co-Cycles in \({SL(2, \mathbb R)}\)

  • Published:
Communications in Mathematical Physics Aims and scope Submit manuscript

Abstract

We prove two results on the rotation number of the skew-product system \({(\omega ,A):(\theta ,y)\in\mathbb T^d\times\mathbb R^2\mapsto (\theta +\omega ,A(\theta)y)\in\mathbb T^d\times\mathbb R^2,}\) where ω is Diophantine and \({A(\theta)\in SL(2, \mathbb R)}\) is homotopic to the identity. On the one hand, we prove that this function has the behavior of a \({\frac{1}{2}-}\) Hölder function. On the other, we show that the length of the gaps has a sub-exponential estimate which depends on its label given by the gap-labeling theorem. We give also an estimate of the complement of the spectrum. These results are obtained by studying the reducibility of the quasi-periodic co-cycle (ω , A).

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Avila A., Jitomirskaya S.: Almost localization and almost reducibility. arXiv: 0805. 1761v1 [math.DS], 2008, to appear in J. Eur. Math. Soc.

  2. Bourgain J.: Hölder regularity of integrated density of states for the almost Mathieu operator in a perturbative regime. Lett. Math. Phys. 51(2), 83–118 (2000)

    Article  MATH  MathSciNet  Google Scholar 

  3. Delyon F., Souillard B.: The rotation number for finite difference operators and its properties. Commu. Math. Phys. 89(3), 415–426 (1983)

    Article  MATH  ADS  MathSciNet  Google Scholar 

  4. Dinaburg E.I., Sinaĭ Ja.G.: The one-dimensional Schrödinger equation with quasiperiodic potential. Funk. Anal. Prilož. 9-4, 8–21 (1975)

    Google Scholar 

  5. Eliasson L.H.: Almost reducibility of linear quasi-periodic systems. Proc. Sympos. Pure Math. 69, 679–705 (2001)

    MathSciNet  Google Scholar 

  6. Eliasson L.H.: Floquet solutions for the 1-dimensional quasi-periodic Schrödinger equation. Commu. Math. Phys. 146-3, 447–482 (1992)

    Article  ADS  MathSciNet  Google Scholar 

  7. Eliasson L.H.: Perturbations of stable invariant tori for Hamiltonian systems. Annali della Scuola Normale Superiore di Pisa. Classe di Scienze. Serie IV 15-1, 115–147 (1988)

    MathSciNet  Google Scholar 

  8. Goldstein M., Schlag W.: Hölder continuity of the integrated density of states for quasi-periodic Schrödinger equations and averages of shifts of subharmonic functions. Ann. Math. (2) 154-1, 155–203 (2001)

    Article  MathSciNet  Google Scholar 

  9. Herman M.-R.: Une méthode pour minorer les exposants de Lyapounov et quelques exemples montrant le caractère local d’un théorème d’Arnol′ d et de Moser sur le tore de dimension 2. Comm. Math. Helv. 58-3, 453–502 (1983)

    Article  MathSciNet  Google Scholar 

  10. Krikorian, R.: Réductibilité des systèmes produits-croisés à valeurs dans des groupes compacts. Astérisque 259(1999)

  11. Moser J., Pöschel J.: An extension of a result by Dinaburg and Sinaĭ on quasiperiodic potentials. Comm. Math. Hel. 59-1, 39–85 (1984)

    Article  Google Scholar 

  12. Rüssmann, H.: On optimal estimates for the solutions of linear partial differential equations of first order with constant coefficients on the torus. Dynamical systems, theory and applications (Rencontres, Battelle Res. Inst., Seattle, Wash. (1974) Lecture Notes in Phys. 38, Berlin-Heidelberg-New York: Springer, 1975, pp. 598–624

  13. Sinaĭ Ja.G.: Structure of the spectrum of a Schrödinger difference operator with almost periodic potential near the left boundary. Funk. Anal. Priloz. 19-1, 34–39 (1985)

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Sana Hadj Amor.

Additional information

Communicated by B. Simon

Rights and permissions

Reprints and permissions

About this article

Cite this article

Hadj Amor, S. Hölder Continuity of the Rotation Number for Quasi-Periodic Co-Cycles in \({SL(2, \mathbb R)}\) . Commun. Math. Phys. 287, 565–588 (2009). https://doi.org/10.1007/s00220-008-0688-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00220-008-0688-x

Keywords

Navigation