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Abstract: We introduce an optimized data vector of cosmic shear measures N. This datavector has high information content, is not sensitive against B-modecontamination and only shows small correlation between data points of differentangular scales. We show that a data vector of the two-point correlationfunction 2PCF in general contains more information on cosmological parameterscompared to a data vector of the aperture mass dispersion. Reason for this isthe fact that lacks the information of the convergence power spectrumP \kappa on large angular scales, which is contained in the 2PCF data vector.Therefore we create a combined data vector N, which retains the advantages of and in addition is also sensitive to the large-scale information ofP \kappa. We compare the information content of the three data vectors byperforming a detailed likelihood analysis and use ray-tracing simulations toderive the covariance matrices. In the last part of the paper we contaminateall data vectors with B-modes on small angular scales and examine theirrobustness against this contamination.The combined data vector stronglyimproves constraints on cosmological parameters compared to . Although,in case of a pure E-mode signal the information content of the 2PCF is higher,in the more realistic case where B-modes are present the 2PCF data vector isstrongly contaminated and yields biased cosmological parameter estimates. Nshows to be robust against this contamination. Furthermore the individual datapoints of N show a much smaller correlation compared to the 2PCF leading to analmost diagonal covariance matrix.



Author: T. Eifler, M. Kilbinger, P. Schneider

Source: https://arxiv.org/



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