Mathematics – Logic
Scientific paper
Nov 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011mnras.418..145j&link_type=abstract
Monthly Notices of the Royal Astronomical Society, Volume 418, Issue 1, pp. 145-169.
Mathematics
Logic
3
Gravitational Lensing: Weak, Methods: Analytical, Methods: Data Analysis, Methods: Statistical, Cosmological Parameters, Large-Scale Structure Of Universe
Scientific paper
Gaussianizing the one-point distribution of the weak gravitational lensing convergence has recently been shown to increase the signal-to-noise ratio contained in two-point statistics. We investigate the information on cosmology that can be extracted from the transformed convergence fields. Employing Box-Cox transformations to determine optimal transformations to Gaussianity, we develop analytical models for the transformed power spectrum, including effects of noise and smoothing. We find that optimized Box-Cox transformations perform substantially better than an offset logarithmic transformation in Gaussianizing the convergence, but both yield very similar results for the signal-to-noise ratio. None of the transformations is capable of eliminating correlations of the power spectra between different angular frequencies, which we demonstrate to have a significant impact on the errors in cosmology. Analytic models of the Gaussianized power spectrum yield good fits to the simulations and produce unbiased parameter estimates in the majority of cases, where the exceptions can be traced back to the limitations in modelling the higher order correlations of the original convergence. In the ideal case, without galaxy shape noise, we find an increase in the cumulative signal-to-noise ratio by a factor of 2.6 for angular frequencies up to ℓ= 1500, and a decrease in the area of the confidence region in the Ωm-σ8 plane, measured in terms of q-values, by a factor of 4.4 for the best performing transformation. When adding a realistic level of shape noise, all transformations perform poorly with little decorrelation of angular frequencies, a maximum increase in signal-to-noise ratio of 34 per cent, and even slightly degraded errors on cosmological parameters. We argue that to find Gaussianizing transformations of practical use, it will be necessary to go beyond transformations of the one-point distribution of the convergence, extend the analysis deeper into the non-linear regime and resort to an exploration of parameter space via simulations.
Joachimi Benjamin
Kiessling Andreas
Taylor Andy N.
No associations
LandOfFree
Cosmological information in Gaussianized weak lensing signals does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Cosmological information in Gaussianized weak lensing signals, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cosmological information in Gaussianized weak lensing signals will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-745102