Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Intrinsic/Extrinsic Density-Ellipticity Correlations and Galaxy-Galaxy
  Lensing   We compute both extrinsic (lensing) and intrinsic contributions to the
(galaxy-)density-ellipticity correlation function, the latter done using
current analytic theories of tidal alignment. The gravitational lensing
contribution has two components: one is analogous to galaxy-galaxy lensing and
the other arises from magnification bias -- that gravitational lensing induces
a modulation of the galaxy density as well as ellipticity. On the other hand,
the intrinsic alignment contribution vanishes, even after taking into account
source clustering corrections, which suggests the density-ellipticity
correlation might be an interesting diagnostic in differentiating between
intrinsic and extrinsic alignments. {\it However}, an important assumption,
commonly adopted by current analytic alignment theories, is the Gaussianity of
the tidal field. Inevitable non-Gaussian fluctuations from gravitational
instability induces a non-zero intrinsic density-ellipticity correlation, which
we estimate. We also argue that non-Gaussian contributions to the intrinsic
{\it ellipticity-ellipticity} correlation are often non-negligible. This leads
to a linear rather than, as is commonly assumed, quadratic scaling with the
power spectrum on sufficiently large scales. Finally, we estimate the
contribution of intrinsic alignment to low redshift galaxy-galaxy lensing
measurements (e.g. SDSS), due to the partial overlap between foreground and
background galaxies: the intrinsic contamination is about 10 - 30 % at 10'.
Uncertainties in this estimate are discussed.

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The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: econ
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The categories of this paper are: bayes-an
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The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-lat