We consider the equation ∆u + uyy + f(x, u) = 0, (x, y) ∈ RN × R (1) where f is sufficiently regular, radially symmetric in x, and f(·, 0) ≡ 0. We give sufficient conditions for the existence of solutions of (1) which are quasiperiodic in y and decaying as |x| → ∞ uniformly in y. Such solutions are found using a center manifold reduction and results from the KAM theory. A required nondegeneracy condition is stated in terms of fu(x, 0) and fuu(x, 0), and is independent of higher-order terms in the Taylor expansion of f(x, ·). In particular, our results apply to some quadratic nonlinearities.
|Original language||English (US)|
|Number of pages||25|
|Journal||Discrete and Continuous Dynamical Systems - Series S|
|State||Published - 2019|
Bibliographical noteFunding Information:
37K55. Key words and phrases. Elliptic equations on the entire space, quasiperiodic solutions, center manifold, Birkhoff normal form, KAM theorem. The first author was supported in part by the NSF Grant DMS-1565388. The second author was supported in part by CONICYT-Chile Becas Chile, Convocatoria 2010. ∗ Corresponding author: P. Poláˇcik.
© 2019 American Institute of Mathematical Sciences. All rights reserved.
- Birkhoff normal form
- Center manifold
- Elliptic equations on the entire space
- KAM theorem
- Quasiperiodic solutions