Electronic Journal of Differential Equations, 
Vol. 2020 (2020), No. 22, pp. 1-17.

Title: Linearization of multi-frequency quasi-periodically forced circle 
       flows beyond Brjuno condition

Authors: Ziyang Liang (Nanjing Univ. of Science and Tech., Nanjing, China)
         Taian Jin    (Nanjing Univ. of Science and Tech., Nanjing, China)
         Jiayi Wang   (Nanjing Univ. of Science and Tech., Nanjing, China)
         Yuan Shan    (Nanjing Audit Univ., Nanjing, China)

Abstract:
 In this article, we considered the linearization of analytic quasi-periodically
 forced circle flows. We generalized the rotational linearization of systems with
 two-dimensional base frequency to systems with any finite dimensional base 
 frequency case.
 Meanwhile, we relaxed the arithmetical limitations  on the base frequencies.
 Our proof is based on a generalized Kolmogorov–Arnold–Moser (KAM) scheme.
 
Submitted September 4, 2019. Published March 12, 2020.
Math Subject Classifications: 37C15, 34C20.
Key Words: Linearization; quasi-periodically forced circle flow; Liouvillean frequency.