Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Completeness of first and second order ODE flows and of Euler-Lagrange
  equations   Two results on the completeness of maximal solutions to first and second
order ordinary differential equations (or inclusions) over complete Riemannian
manifolds, with possibly time-dependent metrics, are obtained. Applications to
Lagrangian mechanics and gravitational waves are given.

24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con