Dullin, H. R.; Ivanov, A. V. Twistless tori near low-order resonances. (English. Russian original) Zbl 1120.37035 J. Math. Sci., New York 128, No. 2, 2754-2760 (2005); translation from Zap. Nauchn. Semin. POMI 300, 135-144 (2003). Summary: We investigate the behavior of the twist near low-order resonances of a periodic orbit or an equilibrium of a Hamiltonian system with two degrees of freedom. Namely, we analyze the case where the Hamiltonian has multiple eigenvalues (the Hamiltonian Hopf bifurcation) or a zero eigenvalue near the equilibrium and the case where the system has a periodic orbit whose multipliers are equal to 1 (the saddle-center bifurcation) or \(-1\) (the period-doubling bifurcation). We show that the twist does not vanish at least in a small neighborhood of the period-doubling bifurcation. For the saddle-center bifurcation and the resonances of the equilibrium under consideration, we prove the existence of a “twistless” torus for sufficiently small values of the bifurcation parameter. An explicit dependence of the energy corresponding to the twistless torus on the bifurcation parameter is derived. Cited in 2 Documents MSC: 37J20 Bifurcation problems for finite-dimensional Hamiltonian and Lagrangian systems 37J40 Perturbations of finite-dimensional Hamiltonian systems, normal forms, small divisors, KAM theory, Arnol’d diffusion 37G40 Dynamical aspects of symmetries, equivariant bifurcation theory Keywords:behavior of the twist; periodic orbit; equilibrium; Hamiltonian system; Hopf bifurcation; saddle-center bifurcation; period-doubling bifurcation × Cite Format Result Cite Review PDF Full Text: DOI References: [1] V. I. Arnold, V. V. Kozlov, and A. I. Neishtadt, Mathematical Aspects of Classical and Celestial Mechanics, Springer-Verlag, Berlin (1988). · Zbl 0885.70001 [2] R. H. Cushman and L. M. Bates, Global Aspects of Classical Integrable Systems, Birkhauser Verlag, Basel (1997). · Zbl 0882.58023 [3] H. R. Dullin, J. D. Meiss, and D. Sterling, ”Generic twistless bifurcations,” Nonlinearity, 13, 203–224 (2000). · Zbl 1005.37024 · doi:10.1088/0951-7715/13/1/310 [4] J. E. Howard and J. Humpherys, ”Nonmonotonic twist maps,” Phys. D, 80, No.3, 256–279 (1995). · Zbl 0888.58055 · doi:10.1016/0167-2789(94)00180-X [5] C. Simo, ”Invariant curves of analytic perturbed nontwist area preserving mappings,” Regul. Chaotic Dyn., 3, 180–195 (1998). · Zbl 0932.37048 · doi:10.1070/rd1998v003n03ABEH000088 [6] A. G. Sokolskij, ”On stability of an autonomous Hamiltonian system with two degrees of freedom under first-order resonance,” Prikl. Mat. Mekh., 41, No.1, 24–33 (1997). This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.