Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A fast and reliable method for the comparison of covariance matrices   Covariance matrices are important tools for obtaining reliable parameter
constraints. Advancements in cosmological surveys lead to larger data vectors
and, consequently, increasingly complex covariance matrices, whose number of
elements grows as the square of the size of the data vector. The most
straightforward way of comparing these matrices involve a full cosmological
analysis, which can be very computationally expensive. Using the concept and
construction of compression schemes, which have become increasingly popular, we
propose a fast and reliable way of comparing covariance matrices. The basic
idea is to only focus on the portion of the covariance matrix that is relevant
for the parameter constraints and quantify, via a fast Monte Carlo simulation,
the difference of a second candidate matrix from the baseline one. To test this
method, we applied it to two covariance matrices that were used to analyse the
cosmic shear measurements for the Dark Energy Survey. We found that the
uncertainties on the parameters change by 2.6\%, a figure in qualitative
agreement with the full cosmological analysis. While our approximate method
cannot replace a full analysis, it may be useful during the development and
validation of codes that estimate covariance matrices. Our method takes roughly
100 times less CPUh than a full cosmological analysis.

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The categories of this paper are: adap-org
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The categories of this paper are: math
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The categories of this paper are: comp-gas
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The categories of this paper are: physics
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The categories of this paper are: hep-lat
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The categories of this paper are: cs
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The categories of this paper are: funct-an
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The categories of this paper are: eess
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The categories of this paper are: ao-sci
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The categories of this paper are: q-bio
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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: hep-th
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The categories of this paper are: nlin
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The categories of this paper are: chem-ph
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The categories of this paper are: patt-sol