Poster
Abstract
: Gravitational
lensing is one of the leading tools in
understanding the dark side of the
Universe. The need for accurate, efficient
and effective methods which are able to
extract this information along with other
cosmological parameters from cosmic shear
data is ever growing. COSEBIs, Complete
Orthogonal Sets of E-/B-Integrals, is a
recently developed statistical measure
that encompasses the complete E-/B-mode
separable information contained in the
shear correlation functions measured on a
finite angular range. Aims. The aim of the
present work is to test the properties of
this newly developed statistics for a
higher-dimensional parameter space and to
generalize and test it for shear
tomography. Methods. We use Fisher
analysis to study the effectiveness of
COSEBIs. We show our results in terms of
figure-of-merit quantities, based on
Fisher matrices. Results. We find that a
relatively small number of COSEBIs modes
is always enough to saturate to the
maximum information level. This number is
always smaller for 'logarithmic COSEBIs'
than for 'linear COSEBIs', and also
depends on the number of redshift bins,
the number and choice of cosmological
parameters, as well as the survey
characteristics. Conclusions. COSEBIs
provide a very compact way of analyzing
cosmic shear data, i.e., all the E-/B-mode
separable second-order statistical
information in the data is reduced to a
small number of COSEBIs modes.
Furthermore, with this method the
arbitrariness in data binning is no longer
an issue since the COSEBIs modes are
discrete. Finally, the small number of
modes also implies that covariances, and
their inverse, are much more conveniently
obtainable, e.g., from numerical
simulations, than for the shear
correlation functions themselves. |
Bibliography
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