Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 2D Simulations of the Line-Driven Instability in Hot-Star Winds: II.
  Approximations for the 2D Radiation Force   We present initial attempts to include the multi-dimensional nature of
radiation transport in hydrodynamical simulations of the small-scale structure
that arises from the line-driven instability in hot-star winds. Compared to
previous 1D or 2D models that assume a purely radial radiation force, we seek
additionally to treat the lateral momentum and transport of diffuse
line-radiation, initially here within a 2D context. A key incentive is to study
the damping effect of the associated diffuse line-drag on the dynamical
properties of the flow, focusing particularly on whether this might prevent
lateral break-up of shell structures at scales near the lateral Sobolev angle
of ca. $1^{\rm o}$. We first explore nonlinear simulations that cast the
lateral diffuse force in the simple, local form of a parallel viscosity.
Second, to account for the lateral mixing of radiation associated with the
radial driving, we next explore models in which the radial force is azimuthally
smoothed over a chosen scale. Third, to account for both the lateral line-drag
and the lateral mixing in a more self-consistent way, we explore further a
method first proposed by Owocki (1999), which uses a restricted 3-ray approach
that combines a radial ray with two oblique rays set to have an impact
parameter $p < R_{\ast}$ within the stellar core. From numerical simulations,
we find that, compared to equivalent 1-ray simulations, the high-resolution
3-ray models show systematically a much higher lateral coherence.... (Full
abstract in paper)

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The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: ao-sci
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The categories of this paper are: alg-geom
1
The categories of this paper are: cs
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The categories of this paper are: q-fin
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The categories of this paper are: stat
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The categories of this paper are: math
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The categories of this paper are: q-alg
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The categories of this paper are: solv-int
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The categories of this paper are: eess
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-th