Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-12-15
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
6 pages, 5 figures, submitted to MNRAS
Scientific paper
We present a new method that deals with the uncertainty in matter-clustering in cosmic shear power spectrum analysis that arises mainly due to poorly understood nonlinear baryonic processes on small-scales. We show that the majority of information about dark energy physics contained in the shear power comes from these small-scales; removing these nonlinear scales from a cosmic shear analysis results in a 50% cut in the accuracy of measurements of dark energy parameters, marginalizing over all other parameters. In this paper we propose a method to recover the information on small-scales by allowing cosmic shear surveys to measure the nonlinear matter power spectrum themselves and marginalize over all possible power spectra using path integrals. Information is still recoverable in these nonlinear regimes from the geometric part of weak lensing. In this self-calibration regime we find we recover 90% of the information on dark energy. Including an informative prior, we find the nonlinear matter power spectrum needs to be accurately known to 1% down to k=50 h/Mpc to recover 99% of the dark energy information. This presents a significant theoretical challenge to understand baryonic effects on the scale of galaxy haloes. However self-calibration from weak lensing may also provide observational input to help constrain baryon physics.
Kitching Thomas D.
Taylor Andy N.
No associations
LandOfFree
On Mitigation of the Uncertainty in Nonlinear Matter Clustering for Cosmic Shear Tomography 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 On Mitigation of the Uncertainty in Nonlinear Matter Clustering for Cosmic Shear Tomography, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On Mitigation of the Uncertainty in Nonlinear Matter Clustering for Cosmic Shear Tomography will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-218195