1202.2046 (Patrick Simon)

Retrieving the 3D matter power spectrum and galaxy biasing parameters from lensing tomography    [PDF]

Patrick Simon

With the availability of galaxy distance indicators in weak lensing surveys, lensing tomography can basically be harnessed to constrain the spatial 3D matter power spectrum over a range in redshift and physical scale. Furthermore, by adding galaxy-galaxy lensing and galaxy clustering this can be extended to probe the 3D galaxy-matter and galaxy-galaxy power spectrum or, alternatively, galaxy biasing parameters. To achieve this aim, this paper introduces and discusses minimum variance estimators and a more general Bayesian approach to statistically invert a set of noisy tomography 2-point correlation functions, measured within a confined opening angle. Both methods are constructed such that they probe deviations of the 3D power spectrum from a fiducial power spectrum. Thereby a direct comparison of theory and data is achieved, the physical scale and redshift of deviations can in principle be identified. By devising a new Monte Carlo technique the measurement noise in the correlators is quantified for a fiducial survey, and the performance of the inversion techniques is tested. We conclude that a shear tomography analysis of near future weak lensing surveys promises fruitful insights into the effect of baryons on the nonlinear matter power spectrum at z<~0.3 around k~2 h/Mpc, and into galaxy biasing (z<~0.5). However, a proper treatment of anticipated systematics -- not included in the mock analysis but discussed here -- is likely to reduce the signal-to-noise in the analysis so that a robust assessment of the 3D matter power spectrum probably asks for a survey area of at least 1000 sdeg. [Abridged]

View original: http://arxiv.org/abs/1202.2046