Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Statistical Study of Weak Lensing by Triaxial Dark Matter Halos:
  Consequences for Parameter Estimation   Measuring the distribution of mass on galaxy cluster scales is a crucial test
of the Lambda CDM model, providing constraints on the nature of dark matter.
Recent work investigating mass distributions of individual galaxy clusters
using gravitational lensing has illuminated potential inconsistencies between
the predictions of structure formation models relating halo mass to
concentration and those relationships as measured in massive clusters. However,
such analyses typically employ only simple spherical halo models with canonical
NFW slopes, while the halos formed in simulations show a range of more complex
features. Here we investigate the impact of such expected deviations from the
canonical NFW halo profile on mass and parameter estimation using weak
gravitational lensing on massive cluster scales. The most important deviation
is halo triaxiality because it is impossible even with fiducial weak lensing
data to fully resolve the three-dimensional structure of the halo due to
lensing's sensitivity only to projected mass. Significant elongation of the
halo along the line of sight can cause the mass and concentration to be
overestimated by as much as 50% and by a factor of 2, respectively, while
foreshortening has the opposite effect. Additionally, triaxial halos in certain
orientations are much better lenses than their spherical counterparts of the
same mass, indicating that clusters chosen for study because of evident lensing
are likely to be drawn from the high-triaxiality end of the halo shape
distribution. While the effects of triaxiality alone may not be enough to fully
explain the very high concentrations reported for some clusters, they go a long
way in easing the tensions between observations and the predictions of the cold
dark matter paradigm. (Abridged)

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The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
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The categories of this paper are: nlin
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The categories of this paper are: ao-sci
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-ex
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The categories of this paper are: stat
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-th
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The categories of this paper are: math-ph
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The categories of this paper are: eess
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The categories of this paper are: physics
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The categories of this paper are: cs