Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The removal of shear-ellipticity correlations from the cosmic shear
  signal via nulling techniques   To render cosmic shear an astronomical tool of high precision, it is
essential to eliminate systematic effects upon its signal, one of the most
significant ones being correlations between the gravitational shear and the
intrinsic ellipticity of source galaxies. Because of the crudeness of current
models of intrinsic alignment, we have developed a model-independent, purely
geometrical method to remove shear-ellipticity correlations. We eliminate the
contributions to a tomographic cosmic shear signal that may be subject to
contamination by shear-ellipticity correlations, making use of the
characteristic dependence of these correlations on redshift. By introducing an
appropriately chosen weight function to the lensing efficiency that nulls
signals stemming from certain distances, new second-order measures of cosmic
shear, free of intrinsic alignment, can be constructed. The loss of information
induced by this nulling technique and the subsequent degradation of constraints
on cosmological parameters is quantified in a likelihood analysis. Concerning
the construction of optimal weight functions, good agreement is achieved
between all approaches considered. For a survey divided into 20 redshift bins
we find that the area of credible regions increases by 20% up to about 50%
after the application of nulling, depending on the cosmological parameters
considered. We demonstrate that due to an optimization of the weight functions
nearly all information is contained in a small subset of the new second-order
measures. The use of a significantly smaller number of redshift bins than 20
for the nulling considerably degrades parameter constraints under conservative
assumptions, emphasizing the need for detailed redshift information.

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The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
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The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
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The categories of this paper are: cond-mat