A new cosmic shear function: Optimised E-B-mode decomposition on a finite interval - Astrophysics > Cosmology and Nongalactic AstrophysicsReportar como inadecuado




A new cosmic shear function: Optimised E-B-mode decomposition on a finite interval - Astrophysics > Cosmology and Nongalactic Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: The decomposition of the cosmic shear field into E- and B-mode is animportant diagnostic in weak gravitational lensing. However, commonly usedtechniques to perform this separation suffer from mode-mixing on very small orvery large scales. We introduce a new E-B-mode decomposition of the cosmicshear two-point correlation on a finite interval. This new statistic isoptimised for cosmological applications, by maximising the signal-to-noiseratio S-N and a figure of merit FoM based on the Fisher matrix of thecosmological parameters Omega m and sigma 8.We improve both S-N and FoM results substantially with respect to therecently introduced ring statistic, which also provides E-B-mode separation ona finite angular range. The S-N FoM is larger by a factor of three two onangular scales between 1 and 220 arc minutes. In addition, it yields betterresults than for the aperture-mass dispersion ^2, with improvements of20% 10% for S-N FoM. Our results depend on the survey parameters, mostimportantly on the covariance of the two-point shear correlation function.Although we assume parameters according to the CFHTLS-Wide survey, our methodand optimisation scheme can be applied easily to any given survey settings andobserving parameters. Arbitrary quantities, with respect to which the E-B-modefilter is optimised, can be defined, therefore generalising the aim and contextof the new shear statistic.



Autor: Liping Fu, Martin Kilbinger

Fuente: https://arxiv.org/







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