Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The effect of a two-fluid atmosphere on relativistic stars   We model the physical behaviour at the surface of a relativistic radiating
star in the strong gravity limit. The spacetime in the interior is taken to be
spherically symmetrical and shear-free. The heat conduction in the interior of
the star is governed by the geodesic motion of fluid particles and a
nonvanishing radially directed heat flux. The local atmosphere in the exterior
region is a two-component system consisting of standard pressureless (null)
radiation and an additional null fluid with nonzero pressure and constant
energy density. We analyse the generalised junction condition for the matter
and gravitational variables on the stellar surface and generate an exact
solution. We investigate the effect of the exterior energy density on the
temporal evolution of the radiating fluid pressure, luminosty, gravitational
redshift and mass flow at the boundary of the star. The influence of the
density on the rate of gravitational collapse is also probed and the strong,
dominant and weak energy conditions are also tested. We show that the presence
of the additional null fluid has a significant effect on the dynamical
evolution of the star.

22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an