0
2013
Impact Factor

# Ru Qu

## Publications:

 Zhang D., Qu R. Persistence of Multiscale Degenerate Invariant Tori for Reversible Systems with Multiscale Degenerate Equilibrium Points 2022, vol. 27, no. 6, pp.  733-756 Abstract In this paper, we focus on the persistence of degenerate lower-dimensional invariant tori with a normal degenerate equilibrium point in reversible systems. Based on the Herman method and the topological degree theory, it is proved that if the frequency mapping has nonzero topological degree and the frequency $\omega_0$ satisfies the Diophantine condition, then the lower-dimensional invariant torus with the frequency $\omega_0$ persists under sufficiently small perturbations. Moreover, the above result can also be obtained when the reversible system is Gevrey smooth. As some applications, we apply our theorem to some specific examples to study the persistence of multiscale degenerate lower-dimensional invariant tori with prescribed frequencies. Keywords: Reversible systems, KAM iteration, topological degree, degenerate lower-dimensional tori, degenerate equilibrium points Citation: Zhang D., Qu R.,  Persistence of Multiscale Degenerate Invariant Tori for Reversible Systems with Multiscale Degenerate Equilibrium Points, Regular and Chaotic Dynamics, 2022, vol. 27, no. 6, pp. 733-756 DOI:10.1134/S1560354722060090