Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Decorrelating the errors of the galaxy correlation function with compact
  transformation matrices   Covariance matrix estimation is a persistent challenge for cosmology, often
requiring a large number of synthetic mock catalogues. The off-diagonal
components of the covariance matrix also make it difficult to show
representative error bars on the 2-point correlation function (2PCF), since
errors computed from the diagonal values of the covariance matrix greatly
underestimate the uncertainties. We develop a routine for decorrelating the
projected and anisotropic 2PCF with simple and scale-compact transformations on
the 2PCF. These transformation matrices are modeled after the Cholesky
decomposition and the symmetric square root of the Fisher matrix. Using mock
catalogues, we show that the transformed projected and anisotropic 2PCF recover
the same structure as the original 2PCF, while producing largely decorrelated
error bars. Specifically, we propose simple Cholesky based transformation
matrices that suppress the off-diagonal covariances on the projected 2PCF by
~95% and that on the anisotropic 2PCF by ~87%. These transformations also serve
as highly regularized models of the Fisher matrix, compressing the degrees of
freedom so that one can fit for the Fisher matrix with a much smaller number of
mocks.

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The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
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The categories of this paper are: eess
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph