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Title: Performance of internal covariance estimators for cosmic shear correlation functions

Data re-sampling methods such as the delete-one jackknife are a common tool for estimating the covariance of large scale structure probes. In this paper we investigate the concepts of internal covariance estimation in the context of cosmic shear two-point statistics. We demonstrate how to use log-normal simulations of the convergence field and the corresponding shear field to carry out realistic tests of internal covariance estimators and find that most estimators such as jackknife or sub-sample covariance can reach a satisfactory compromise between bias and variance of the estimated covariance. In a forecast for the complete, 5-year DES survey we show that internally estimated covariance matrices can provide a large fraction of the true uncertainties on cosmological parameters in a 2D cosmic shear analysis. The volume inside contours of constant likelihood in the $$\Omega_m$$-$$\sigma_8$$ plane as measured with internally estimated covariance matrices is on average $$\gtrsim 85\%$$ of the volume derived from the true covariance matrix. The uncertainty on the parameter combination $$\Sigma_8 \sim \sigma_8 \Omega_m^{0.5}$$ derived from internally estimated covariances is $$\sim 90\%$$ of the true uncertainty.
 [1] ;  [1] ;  [2] ;  [1]
  1. Univ. Observatory Munich, Munich (Germany); Max Planck Institute for Extraterrestrial Physics, Garching (Germany)
  2. California Institute of Technology, Pasadena, CA (United States)
Publication Date:
Report Number(s):
arXiv:1508.00895; FERMILAB-PUB-16-182-AE
Journal ID: ISSN 0035-8711; 1386645
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 456; Journal Issue: 3; Journal ID: ISSN 0035-8711
Royal Astronomical Society
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; methods: data analysis; methods: statistical; cosmological parameters; large-scale structure of Universe; cosmic shear; covariance; jackknife; angular correlation function
OSTI Identifier: