Performance of internal covariance estimators for cosmic shear correlation functions
Data resampling methods such as the deleteone 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 twopoint statistics. We demonstrate how to use lognormal 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 subsample covariance can reach a satisfactory compromise between bias and variance of the estimated covariance. In a forecast for the complete, 5year 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.
 Authors:

^{[1]};
^{[1]};
^{[2]};
^{[1]}
 Univ. Observatory Munich, Munich (Germany); Max Planck Institute for Extraterrestrial Physics, Garching (Germany)
 California Institute of Technology, Pasadena, CA (United States)
 Publication Date:
 Report Number(s):
 arXiv:1508.00895; FERMILABPUB16182AE
Journal ID: ISSN 00358711; 1386645
 Grant/Contract Number:
 AC0207CH11359
 Type:
 Accepted Manuscript
 Journal Name:
 Monthly Notices of the Royal Astronomical Society
 Additional Journal Information:
 Journal Volume: 456; Journal Issue: 3; Journal ID: ISSN 00358711
 Publisher:
 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) (SC25)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 79 ASTRONOMY AND ASTROPHYSICS; methods: data analysis; methods: statistical; cosmological parameters; largescale structure of Universe; cosmic shear; covariance; jackknife; angular correlation function
 OSTI Identifier:
 1254158
Friedrich, O., Seitz, S., Eifler, T. F., and Gruen, D.. Performance of internal covariance estimators for cosmic shear correlation functions. United States: N. p.,
Web. doi:10.1093/mnras/stv2833.
Friedrich, O., Seitz, S., Eifler, T. F., & Gruen, D.. Performance of internal covariance estimators for cosmic shear correlation functions. United States. doi:10.1093/mnras/stv2833.
Friedrich, O., Seitz, S., Eifler, T. F., and Gruen, D.. 2015.
"Performance of internal covariance estimators for cosmic shear correlation functions". United States.
doi:10.1093/mnras/stv2833. https://www.osti.gov/servlets/purl/1254158.
@article{osti_1254158,
title = {Performance of internal covariance estimators for cosmic shear correlation functions},
author = {Friedrich, O. and Seitz, S. and Eifler, T. F. and Gruen, D.},
abstractNote = {Data resampling methods such as the deleteone 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 twopoint statistics. We demonstrate how to use lognormal 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 subsample covariance can reach a satisfactory compromise between bias and variance of the estimated covariance. In a forecast for the complete, 5year 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.},
doi = {10.1093/mnras/stv2833},
journal = {Monthly Notices of the Royal Astronomical Society},
number = 3,
volume = 456,
place = {United States},
year = {2015},
month = {12}
}