Korkut, Luka; Vlah, Domagoj; Županović, Vesna Geometrical properties of systems with spiral trajectories in \(\mathbb R^3\). (English) Zbl 1342.37025 Electron. J. Differ. Equ. 2015, Paper No. 276, 19 p. (2015). Summary: We study a class of second-order nonautonomous differential equations, and the corresponding planar and spatial systems, from the geometrical point of view. The oscillatory behavior of solutions at infinity is measured by oscillatory and phase dimensions, The oscillatory dimension is defined as the box dimension of the reflected solution near the origin, while the phase dimension is defined as the box dimension of a trajectory of the planar system in the phase plane. Using the phase dimension of the second-order equation we compute the box dimension of a spiral trajectory of the spatial system. This phase dimension of the second-order equation is connected to the asymptotic of the associated Poincare map. Also, the box dimension of a trajectory of the reduced normal form with one eigenvalue equals zero, and a pair of pure imaginary eigenvalues is computed when limit cycles bifurcate from the origin. Cited in 1 Document MSC: 37C45 Dimension theory of smooth dynamical systems 37G10 Bifurcations of singular points in dynamical systems 34C15 Nonlinear oscillations and coupled oscillators for ordinary differential equations 28A80 Fractals Keywords:spiral; chirp; box dimension; rectifiability; oscillatory dimension; phase dimension; limit cycle PDFBibTeX XMLCite \textit{L. Korkut} et al., Electron. J. Differ. Equ. 2015, Paper No. 276, 19 p. (2015; Zbl 1342.37025) Full Text: arXiv EMIS