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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.
Authors:
 [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:
AC02-07CH11359
Type:
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
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) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
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:
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 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.},
doi = {10.1093/mnras/stv2833},
journal = {Monthly Notices of the Royal Astronomical Society},
number = 3,
volume = 456,
place = {United States},
year = {2015},
month = {12}
}