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| Paper: |
Decomposition of Cosmic Shear E-/B-Mode on a Finite Interval |
| Volume: |
446, Galaxy Evolution: Infrared to Millimeter Wavelength Perspective |
| Page: |
393 |
| Authors: |
Xu, J.; Fu, L.; Kilbinger, M. |
| Abstract: |
The decomposition of the cosmic shear field into E- and B-mode is an
important diagnostic in weak gravitational lensing. However,
commonly used techniques to perform this separation suffer from
mode-mixing on very small or very large scales. We introduce a new
E-/B-mode decomposition of the cosmic shear two-point correlation on
a finite interval. This new statistic is optimised for cosmological
applications, by maximising the signal-to-noise ratio (S/N) and a
figure of merit (FoM) based on the Fisher matrix of the cosmological
parameters Ωm and σ8.
We improve both S/N and FoM results substantially with respect to
the recently introduced ring statistic, which also provides
E-/B-mode separation on a finite angular range. The S/N (FoM) is
larger by a factor of three (two) on angular scales between 1 and
220 arc minutes. In addition, it yields better results than for the
aperture-mass dispersion langle Map2 rangle, with
improvements of 20% (10%) for S/N (FoM). Our results depend on
the survey parameters, most importantly on the covariance of the
two-point shear correlation function. Although we assume parameters
according to the CFHTLS-Wide survey, our method and optimisation
scheme can be applied easily to any given survey settings and
observing parameters. Arbitrary quantities, with respect to which
the E-/B-mode filter is optimised, can be defined, therefore
generalising the aim and context of the new shear statistic. |
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