English

On Hamiltonian flows whose orbits are straight lines

Dynamical Systems 2013-04-12 v1

Abstract

We consider real analytic Hamiltonians whose flow depends linearly on time. Trivial examples are Hamiltonians H(q,p)H(q,p) that do not depend on the coordinate qq. By a theorem of Moser, every polynomial Hamiltonian of degree 3 reduces to such a qq-independent Hamiltonian via a linear symplectic change of variables. We show that such a reduction is impossible, in general, for polynomials of degree 4 or higher. But we give a condition that implies linear-symplectic conjugacy to another simple class of Hamiltonians. The condition is shown to hold for all nondegenerate Hamiltonians that are homogeneous of degree 4.

Keywords

Cite

@article{arxiv.1304.3377,
  title  = {On Hamiltonian flows whose orbits are straight lines},
  author = {Hans Koch and Héctor E. Lomelí},
  journal= {arXiv preprint arXiv:1304.3377},
  year   = {2013}
}
R2 v1 2026-06-21T23:58:09.676Z