Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Focusing of world-lines in Weyl gravity   We study the evolution of time-like congruences in the vacuum solutions of
Weyl conformal theory of gravity. Using the Raycaudhuri equation, we show that
for positive values of the coeffcient of the linear term in the solution and in
the absence of the cosmological constant, the incoming rays converge. The
evolution of the congruence for negative values is investigated for different
values of the parameters. The behavior of the congruence under conformal
transformations is also studied.

18
The categories of this paper are: econ
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph