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Non-perturbative reducibility of three-dimensional skew symmetric systems without any non-degeneracy condition

Published online by Cambridge University Press:  18 February 2025

DONGFENG ZHANG*
Affiliation:
School of Mathematics, Southeast University, Nanjing 210096, PR China
JUNXIANG XU
Affiliation:
School of Mathematics, Southeast University, Nanjing 210096, PR China
*

Abstract

We consider the system $\dot {x}=(A+ P(t,\epsilon )) x, x\in \mathbb {R}^{3}, $ where $A, P$ are both three-dimensional skew symmetric matrices, A is a constant matrix with eigenvalues $\pm i\unicode{x3bb} $ and 0, $P(t,\epsilon )$ is $C^{m}(m=0,1)$-smooth in $\epsilon $ and analytic quasi-periodic with respect to t with basic frequencies $\omega =(1,\alpha )$, with $\alpha $ being irrational, and $\epsilon $ is a small parameter. Under some non-resonant conditions about the basic frequencies and the eigenvalues of the constant matrix and without any non-degeneracy condition, it is proved that for many sufficiently small parameters, this system can be reduced to a rotation system. Furthermore, if the basic frequencies satisfy that $ 0\leq \beta (\alpha ) < r,$ where $\beta (\alpha )=\limsup \nolimits _{n\rightarrow \infty } {\ln q_{n+1}}/{q_{n}},$ $q_{n}$ is the sequence of denominations of the best rational approximations for $\alpha \in \mathbb {R} \setminus \mathbb {Q},$ r is the initial radius of analytic domain, it is proved that for many sufficiently small parameters, this system can be reduced to a constant system.

Type
Original Article
Copyright
© The Author(s), 2025. Published by Cambridge University Press

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References

Avila, A., Fayad, B. and Krikorian, R.. A KAM scheme for SL(2,R) cocycles with Liouvillean frequencies. Geom. Funct. Anal. 21 (2011), 10011019.CrossRefGoogle Scholar
Avila, A. and Jitomirskaya, S.. Almost localization and almost reducibility. J. Eur. Math. Soc. (JEMS) 12 (2010), 93131.CrossRefGoogle Scholar
Bambusi, D.. Reducibility of 1-d Schrödinger equation with time quasiperiodic unbounded perturbations, II. Comm. Math. Phys. 353(1) (2017), 353378.CrossRefGoogle Scholar
Bambusi, D.. Reducibility of 1-d Schrödinger equation with time quasiperiodic unbounded perturbations, I. Trans. Amer. Math. Soc. 370(3) (2018), 18231865.CrossRefGoogle Scholar
Bambusi, D., Grébert, B., Maspero, A. and Robert, D.. Reducibility of the quantum harmonic oscillator in d-dimensions with polynomial time-dependent perturbation. Anal. PDE 11(3) (2018), 775799.CrossRefGoogle Scholar
Bogoljubov, N. N., Mitropoliskii, J. A. and Samoilenko, A. M.. Methods of Accelerated Convergence in Nonlinear Mechanics. Hindustan Publishing Corp., Delhi; Springer-Verlag, Berlin, 1976; translated from the Russian by V. Kumar and edited by I. N. Sneddon.CrossRefGoogle Scholar
Chavaudret, C.. Reducibility of quasi-periodic cocycles in linear Lie groups. Ergod. Th. & Dynam. Sys. 31 (2010), 741769.CrossRefGoogle Scholar
Chavaudret, C.. Strong almost reducibility for analytic and Gevrey quasi-periodic cocycles. Bull. Soc. Math. France 141 (2013), 47106.CrossRefGoogle Scholar
Chavaudret, C. and Marmi, S.. Reducibility of quasiperiodic cocycles under a Brjuno–Rüssmann arithmetical condition. J. Mod. Dyn. 6(1) (2012), 5978.CrossRefGoogle Scholar
Cheng, H., Si, W. and Si, J.. Whiskered tori for forced beam equations with multi-dimensional Liouvillean frequency. J. Dynam. Differential Equations 32(2) (2020), 705739.CrossRefGoogle Scholar
Dinaburg, E. I. and Sinai, Y. G.. The one dimensional Schrödinger equation with quasi-perioidc potential. Funct. Anal. Appl. 9 (1975), 821.Google Scholar
Eliasson, L. H.. Floquet solutions for the 1-dimensional quasi-periodic Schrödinger equation. Comm. Math. Phys. 146 (1992), 447482.CrossRefGoogle Scholar
Eliasson, L. H.. Ergodic skew-systems on $\mathbb{T}^d\times SO(3,\mathbb{R})$ $.$ Ergod. Th. & Dynam. Sys. 22 (2002), 14291449.CrossRefGoogle Scholar
Eliasson, L. H., Fayad, B. and Krikorian, R.. Around the stability of KAM tori. Duke Math. J. 164(9) (2015), 17331775.CrossRefGoogle Scholar
Eliasson, L. H. and Kuksin, S. B.. On reducibility of Schrödinger equations with quasi-periodic in time potentials. Comm. Math. Phys. 286 (2009), 125135.CrossRefGoogle Scholar
Fayad, B. and Krikorian, R.. Herman’s last geometric theorem. Ann. Sci. Éc. Norm. Supér. (4) 42 (2009), 193219.CrossRefGoogle Scholar
Her, H. and You, J.. Full measure reducibility for generic one-parameter family of quasi-periodic linear systems. J. Dynam. Differential Equations 20 (2008), 831866.CrossRefGoogle Scholar
Hou, X. and You, J.. Almost reducibility and non-perturbative reducibility of quasi-periodic linear systems. Invent. Math. 190 (2012), 209260.CrossRefGoogle Scholar
Jorba, À. and Simó, C.. On the reducibility of linear differential equation with quasi-perioidc coefficients. J. Differential Equations 98(1) (1992), 111124.CrossRefGoogle Scholar
Jorba, À. and Simó, C.. On quasi-periodic perturbations of elliptic equilibrium points. SIAM J. Math. Anal. 27(6) (1996), 17041737.CrossRefGoogle Scholar
Krikorian, R.. Global density of reducible quasi-periodic cocycles on $\mathbb{T}^1\times SU(2)$ $.$ Ann. of Math. (2) 154 (2001), 269326.CrossRefGoogle Scholar
Krikorian, R., Wang, J., You, J. and Zhou, Q.. Linearization of quasi-periodically forced circle flow beyond Brjuno condition. Comm. Math. Phys. 358(1) (2018), 81100.CrossRefGoogle Scholar
Leguil, M., You, J., Zhao, Z. and Zhou, Q.. Asymptotics of spectral gaps of quasi-periodic Schrödinger operators. Camb. J. Math. 12(4) (2024), 753830.CrossRefGoogle Scholar
Lopes Dias, J.. A normal form theorem for Brjuno skew systems through renormalization. J. Differential Equations 230(1) (2006), 123.CrossRefGoogle Scholar
Lopes Dias, J.. Brjuno condition and renormalization for Poincaré flows. Discrete Contin. Dyn. Syst. 15(2) (2006), 641656.CrossRefGoogle Scholar
Lopes Dias, J. and Pedro Gaivão, J.. Linearization of Gevrey flows on $\mathbb{T}^d$ with a Brjuno type arithmetical condition. J. Differential Equations 267(12) (2019), 71677212.CrossRefGoogle Scholar
Moser, J. and Pöschel, J.. An extension of a result by Dinaburg and Sinai on quasi-perioidc potentials. Comment. Math. Helv. 59 (1984), 3985.CrossRefGoogle Scholar
Pöschel, J.. KAM à la R. Regul. Chaotic Dyn. 16 (2011), 1723.CrossRefGoogle Scholar
Puig, J.. A nonperturbative Eliasson’s reducibility theorem. Nonlinearity 19 (2006), 355376.CrossRefGoogle Scholar
Rüssmann, H.. On the one dimensional Schrödinger equation with a quasi-perioidc potential. Ann. New York Acad. Sci. 357 (1980), 90107.CrossRefGoogle Scholar
Rüssmann, H.. Convergent transformations into a normal form in analytic Hamiltonian systems with two degrees of freedom on the zero energy surface near degenerate elliptic singularities. Ergod. Th. & Dynam. Sys. 24 (2004), 17871832.CrossRefGoogle Scholar
Wang, F., Cheng, H. and Si, J.. Response solution to ill-posed Boussinesq equation with quasi-periodic forcing of Liouvillean frequency. J. Nonlinear Sci. 30(2) (2020), 657710.CrossRefGoogle Scholar
Wang, J., You, J. and Zhou, Q.. Response solutions for quasi-periodically forced harmonic oscillators. Trans. Amer. Math. Soc. 369 (2017), 42514274.CrossRefGoogle Scholar
Wang, X., Xu, J. and Zhang, D.. On the persistence of degenerate lower-dimensional tori in reversible systems. Ergod. Th. & Dynam. Sys. 35 (2015), 23112333.CrossRefGoogle Scholar
Xu, X., Si, W. and Si, J.. Stoker’s problem for quasi-periodically forced reversible systems with multidimensional Liouvillean frequency. SIAM J. Appl. Dyn. Syst. 19(4) (2020), 22862321.CrossRefGoogle Scholar
You, J. and Zhou, Q.. Embedding of analytic quasi-periodic cocycles into analytic quasi-periodic linear systems and its applications. Comm. Math. Phys. 323 (2013), 9751005.CrossRefGoogle Scholar
Zhang, D. and Xu, J.. Invariant curves of analytic reversible mappings under Brjuno–Rüssmann’s non-resonant condition. J. Dynam. Differential Equations 26 (2014), 9891005.CrossRefGoogle Scholar
Zhang, D. and Xu, J.. Reducibility of a class of nonlinear quasi-periodic systems with Liouvillean basic frequencies. Ergod. Th. & Dynam. Sys. 41(6) (2021), 18831920.CrossRefGoogle Scholar
Zhang, D., Xu, J., Wu, H. and Xu, X.. On the reducibility of linear quasi-periodic systems with Liouvillean basic frequencies and multiple eigenvalues. J. Differential Equations 269 (2020), 1067010716.CrossRefGoogle Scholar
Zhang, D., Xu, J. and Xu, X.. Reducibility of three dimensional skew symmetric system with Liouvillean basic frequencies. Discrete Contin. Dyn. Syst. 38(6) (2018), 28512877.CrossRefGoogle Scholar
Zhou, Q. and Wang, J.. Reducibility results for quasiperiodic cocycles with Liouvillean frequency. J. Dynam. Differential Equations 24 (2012), 6183.CrossRefGoogle Scholar