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JOURNALS // Regular and Chaotic Dynamics // Archive

Regul. Chaotic Dyn., 2023 Volume 28, Issue 4-5, Pages 707–730 (Mi rcd1229)

This article is cited in 1 paper

Special Issue: On the 80th birthday of professor A. Chenciner

A Simple Proof of Gevrey Estimates for Expansions of Quasi-Periodic Orbits: Dissipative Models and Lower-Dimensional Tori

Adrián P. Bustamantea, Rafael de la Llaveb

a Department of Mathematics, University of Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma, Italy
b School of Mathematics, Georgia Institute of Technology, 686 Cherry St., 30332-1160 Atlanta GA, USA

Abstract: We consider standard-like/Froeschlé dissipative maps with a dissipation and nonlinear perturbation. That is,
$$ T_\varepsilon(p,q) = \left( (1 - \gamma \varepsilon^3) p + \mu + \varepsilon V'(q), q + (1 - \gamma \varepsilon^3) p + \mu + \varepsilon V'(q) \bmod 2 \pi \right) $$
where $p \in {\mathbb R}^D$, $q \in {\mathbb T}^D$ are the dynamical variables. We fix a frequency $\omega \in {\mathbb R}^D$ and study the existence of quasi-periodic orbits. When there is dissipation, having a quasi-periodic orbit of frequency $\omega$ requires selecting the parameter $\mu$, called the drift.
We first study the Lindstedt series (formal power series in $\varepsilon$) for quasi-periodic orbits with $D$ independent frequencies and the drift when $\gamma \ne 0$. We show that, when $\omega$ is irrational, the series exist to all orders, and when $\omega$ is Diophantine, we show that the formal Lindstedt series are Gevrey. The Gevrey nature of the Lindstedt series above was shown in [3] using a more general method, but the present proof is rather elementary.
We also study the case when $D = 2$, but the quasi-periodic orbits have only one independent frequency (lower-dimensional tori). Both when $\gamma = 0$ and when $\gamma \ne 0$, we show that, under some mild nondegeneracy conditions on $V$, there are (at least two) formal Lindstedt series defined to all orders and that they are Gevrey.

Keywords: Lindstedt series, Gevrey series, asymptotic expansions, resonances, whiskered tori.

MSC: 35C20, 34K26, 37J40, 70K43, 70K70

Received: 30.03.2023
Accepted: 07.09.2023

Language: English

DOI: 10.1134/S1560354723040123



© Steklov Math. Inst. of RAS, 2026