English

Epicycles in hyperbolic sky

Dynamical Systems 2018-12-20 v2

Abstract

Consider a swiveling arm on an oriented complete riemannian surface composed of three geodesic intervals, attached one to another in a chain. Each interval of the arm rotates with constant angular velocity around its extremity contributing to a common motion of the arm. Does the extremity of such a chain have an asymptotic velocity ? This question for the motion in the euclidian plane, formulated by J.-L. Lagrange, was solved by P. Hartman, E. R. Van Kampen, A. Wintner. We generalize their result to motions on any complete orientable surface of non-zero (and even non-constant) curvature. In particular, we give the answer to Lagrange's question for the movement of a swiveling arm on the hyperbolic plane. The question we study here can be seen as a dream about celestial mechanics on any riemannian surface : how many turns around the Sun a satellite of a planet in the heliocentric epicycle model would make in one billion years ?

Cite

@article{arxiv.1704.01339,
  title  = {Epicycles in hyperbolic sky},
  author = {Olga Romaskevich},
  journal= {arXiv preprint arXiv:1704.01339},
  year   = {2018}
}

Comments

25 pages, 16 figures

R2 v1 2026-06-22T19:08:13.760Z