We present an example of a three-degrees-of-freedom polynomial Hamilton function with a critical point characterized by indefinite quadratic part with a Morse index 2. This function generates a Hamiltonian system wherein all eigenvalues equal $ \pm \mathrm{i} $, but it lacks small-amplitude periodic solutions with a period $ \approx 2\pi. $
Citation: Henryk Żoła̧dek. An example in Hamiltonian dynamics[J]. Communications in Analysis and Mechanics, 2024, 16(2): 431-447. doi: 10.3934/cam.2024020
We present an example of a three-degrees-of-freedom polynomial Hamilton function with a critical point characterized by indefinite quadratic part with a Morse index 2. This function generates a Hamiltonian system wherein all eigenvalues equal $ \pm \mathrm{i} $, but it lacks small-amplitude periodic solutions with a period $ \approx 2\pi. $
[1] | A. M. Lyapunov, The General Problem of the Stability of Motion, Taylor & Francis Group, London, 1992. https://doi.org/10.1115/1.2901415 |
[2] | H. Żoła̧dek, Normal forms, invariant manifolds and Lyapunov theorems, Commun. Analysis Mech., 15 (2023), 300–341. https://doi.org/10.3934/cam.2023016 |
[3] | H. Poincaré, Mémoire sur les Courbes Définies par une Équation Différentielle, in: Œuvres de Henri Poincaré 1, Gauthier–Villars, Paris, 1951. |
[4] | D. S. Schmidt, Periodic solutions near a resonant equilibrium of a Hamiltonian system, Celestial Mech., 9 (1974), 81–103. https://doi.org/10.1007/BF01236166 doi: 10.1007/BF01236166 |
[5] | A. Weinstein, Normal modes for nonlinear Hamiltonian systems, Invent. Math, 20 (1973), 47–57. https://doi.org/10.1007/BF01405263 doi: 10.1007/BF01405263 |
[6] | J. Mawhin, J. Willem, Critical Point Theory and Hamiltonian Systems, Springer, New York, 1989. https://doi.org/10.1007/971-1-4757-2061-7 |
[7] | J. Moser, Periodic orbits near an equilibrium and a theorem by Alan Weinstein, Comm. Pure Appl. Math, 29 (1976), 724–747. https://doi.org/10.1016/s0304-0208(08)71098-3 doi: 10.1016/s0304-0208(08)71098-3 |
[8] | A. Szulkin, Bifurcation of strongly indefinite functionals and a Liapunov type theorem for Hamiltonian systems, Differential Integral Equations, 7 (1994), 217–234. https://doi.org/10.57262/die/1369926976 doi: 10.57262/die/1369926976 |
[9] | E. N. Dancer, S. Rybicki, A note on periodic solutions of autonomous Hamiltonian systems emanating from degenerate stationary solutions, Differential Integral Equations, 12 (1999), 147–160. https://doi.org/10.57262/die/1367265626 doi: 10.57262/die/1367265626 |
[10] | A. Gołȩbiewska, E. Pérez-Chavela, S. Rybicki, A. Ureña, Bifurcation of closed orbits from equilibria of Newtonian systems with Coriolis forces, J. Differential Equations, 338 (2022), 441–473. https://doi.org/10.1016/j.jde.2022.08.004 doi: 10.1016/j.jde.2022.08.004 |
[11] | D. Strzelecki, Periodic solutions of symmetric Hamiltonian systems, Arch. Rational Mech. Anal, 237 (2020), 921–950. https://doi.org/10.1007/s00205-020-01522-6 doi: 10.1007/s00205-020-01522-6 |
[12] | A. van Straten, A note on the number of periodic orbits near a resonant equilibrium point, Nonlinearity, 2 (1989), 445–458. https://doi.org/10.1007/BF02570469 doi: 10.1007/BF02570469 |
[13] | G. D. Birkhoff, Dynamical Systems, Amer. Math. Soc., Providence, 1927. https://doi.org/10.1016/B978-044450871-3/50149-2 |
[14] | V. I. Arnold, V. V. Kozlov, A. I. Neishtadt, Mathematical Aspects of the Mathematical and Celestial Mechanics, Encyclopaedia of Math. Sci., Dynamical Systems, 3, Springer, New York, 1988. https://doi.org/10.2307/3619341 |