Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spread of Matter Over a Neutron-Star Surface During Disk Accretion   Disk accretion onto a slowly rotating neutron star with a weak magnetic field
$H < 3\times 10^8$ gauss is considered in a wide range of luminosities $1/100 <
L/L_{edd} < 1,$ where $L_{edd}$ is the Eddington luminosity. We construct a
theory for the deceleration of rotation and the spread of matter over the
stellar surface in the shallow-water approximation. The rotation slows down due
to friction against the dense underlying layers. The deceleration of Keplerian
rotation and the energy release take place on the stellar surface in a
latitudinal belt whose meridional width rises with increasing $L.$ The combined
effect of centrifugal force and radiation pressure gives rise to two
latitudinal rings of enhanced brightness which are symmetric around the equator
in the upper and lower hemispheres. They lie near the edges of differentially
rotating and radiating upper and lower belts. The bright rings shift from the
equatorial zone to higher latitudes when the luminosity $L$ rises. The ring
zones are characterized by a minimum surface density and, accordingly, by a
maximum meridional spread velocity. At a low accretion rate and luminosity, the
released energy is removed through the comptonization of low-frequency photons.

17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn