Collinear motions in constant curvature spaces, and coplanar motions in ℝ^4
Abstract
A collinear motion of an n-body problem is one in which the n-bodies always lie along some, possibly moving, geodesic during their evolution. We prove that every collinear motion of n≥ 3 bodies in a constant non-zero curvature space is necessarily contained in some fixed constant curvature space of dimension at most three. For natural systems admitting energy and angular momentum integrals, we further show that every such motion is necessarily a relative equilibrium: evolving under uniform rotation while maintaining constant mutual distances. These results extend certain classical results on collinear motions in Euclidean spaces, initiated by P. Pizzetti, to general spaces of constant curvature. The same methods also yield a partial answer to a question of A. Wintner. Namely, we show that any concave and always coplanar motion in the Euclidean 4-body problem, where the moving plane containing the bodies sweeps out an ℝ4, must be self-similar: maintaining constant mutual distance ratios over the motion.
Related
- The Morse Index, Nullity and Jacobi Fields of Constant-Curvature Minimal 2-Spheres in Complex Projective Spaces
- Constant mean curvature disks with circular boundary
- Hypersurfaces with constant sectional curvature of a product of two space forms
- Constant mean curvature disks with circular boundary in the $3$-sphere and in hyperbolic space
- Rigidity of conformal metrics with constant sixth-order Q-curvature
BibTeX
@misc{barreraanzaldo2026collinear,
title = {{Collinear motions in constant curvature spaces, and coplanar motions in $\mathbbR^4$}},
author = {Carlos Barrera-Anzaldo and Abimael Bengochea and Connor Jackman and Ernesto Pérez-Chavela},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.30567},
eprint = {2610.30567},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.30567},
}
RIS
TY - UNPB
TI - Collinear motions in constant curvature spaces, and coplanar motions in ℝ^4
AU - Carlos Barrera-Anzaldo
AU - Abimael Bengochea
AU - Connor Jackman
AU - Ernesto Pérez-Chavela
PY - 2026
DA - 2026/10/22
PB - arXiv
DO - 10.48550/arxiv.2610.30567
UR - https://arxiv.org/abs/2610.30567
AB - A collinear motion of an n-body problem is one in which the n-bodies always lie along some, possibly moving, geodesic during their evolution. We prove that every collinear motion of n≥ 3 bodies in a constant non-zero curvature space is necessarily contained in some fixed constant curvature space of dimension at most three. For natural systems admitting energy and angular momentum integrals, we further show that every such motion is necessarily a relative equilibrium: evolving under uniform rotation while maintaining constant mutual distances. These results extend certain classical results on collinear motions in Euclidean spaces, initiated by P. Pizzetti, to general spaces of constant curvature. The same methods also yield a partial answer to a question of A. Wintner. Namely, we show that any concave and always coplanar motion in the Euclidean 4-body problem, where the moving plane containing the bodies sweeps out an ℝ^4, must be self-similar: maintaining constant mutual distance ratios over the motion.
ER -