English

A geometric space without conjugate points

Differential Geometry 2010-09-20 v1

Abstract

From a spray space SS on a manifold MM we construct a new geometric space PP of larger dimension with the following properties: 1. Geodesics in PP are in one-to-one correspondence with parallel Jacobi fields of MM. 2. PP is complete if and only if SS is complete. 3. If two geodesics in PP meet at one point, the geodesics coincide on their common domain, and PP has no conjugate points. 4. There exists a submersion π ⁣:PM\pi\colon P \to M that maps geodesics in PP into geodesics on MM. Space PP is constructed by first taking two complete lifts of spray SS. This will give a spray SccS^{cc} on the second iterated tangent bundle TTMTTM. Then space PP is obtained by restricting tangent vectors of geodesics for SccS^{cc} onto a suitable (2dimM+2)(2\dim M+2)-dimensional submanifold of TTTMTTTM. Due to the last restriction, space PP is not a spray space. However, the construction shows that conjugate points can be removed if we add dimensions and relax assumptions on the geometric structure.

Keywords

Cite

@article{arxiv.0809.4246,
  title  = {A geometric space without conjugate points},
  author = {Ioan Bucataru and Matias F. Dahl},
  journal= {arXiv preprint arXiv:0809.4246},
  year   = {2010}
}
R2 v1 2026-06-21T11:23:50.971Z