Modeling of weak-lensing statistics

I. Power spectrum and bispectrum

¹ Institut de Physique Théorique, CEA Saclay, 91191 Gif-sur-Yvette, France
e-mail: patrick.valageas@cea.fr
² Department of Physics, Nagoya University, 464-8602 Nagoya, Japan
³ Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8568, Japan

Received: 30 November 2011
Accepted: 19 April 2012

Abstract

Aims. We investigate the performance of an analytic model of the 3D matter distribution, which combines perturbation theory with halo models, for weak-lensing statistics.

Methods. We compare our predictions for the weak-lensing convergence power spectrum and bispectrum with numerical simulations and fitting formulas proposed in previous works.

Results. We find that this model provides better agreement with simulations than published fitting formulas. This shows that building on systematic and physically motivated models is a promising approach. Moreover, this makes explicit the link between the weak-lensing statistics and the underlying properties of the 3D matter distribution, as a function of scale ℓ. Thus, we obtain the contributions to the lensing power spectrum and bispectrum that arise from perturbative terms (complete up to one-loop) and nonperturbative terms (e.g., “1-halo” term). Finally, we show that this approach recovers the dependence on cosmology (for realistic scenarios).