Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Evolution and Gravitational Collapse of a Toroidal Vortex   The evolution and collapse of a gaseous toroidal vortex under the action of
self-gravitation are considered using the Hamiltonian mechanics approach. It is
shown that evolution occurs in three main stages separated by characteristic
time scales. First, a compression along the small radius to a quasi-equilibrium
state takes place, followed by a slower compression along the large radius to a
more stable compact vortex object. In the latter stage, the possibility of
effective scattering and ejection of particles along the vortex axis (jet
formation) is detected. As a result, mass, energy, and momentum losses take
place, and the vortex collapses.

5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci