Non-linear weak lensing forecasts

TL;DR

This paper examines how non-linear corrections affect dark energy parameter estimates from weak lensing, highlighting discrepancies between models and simulations especially when w(z) differs from -1.

Contribution

It demonstrates the limitations of halofit expressions for non-LCDM models and emphasizes the importance of accurate non-linear modeling in dark energy studies.

Findings

Halofit expressions can significantly misestimate parameters for w(z)≠-1.

Discrepancies are especially large for models with w'(z=0)>0.

Neglecting dark energy degrees of freedom can bias matter density estimates.

Abstract

We investigate the impact of non-linear corrections on dark energy parameter estimation from weak lensing probes. We find that using halofit expressions, suited to LCDM models, implies substantial discrepancies with respect to results directly obtained from N-body simulations, when w(z)\neq-1. Discrepancies appear strong when using models with w'(z=0)>0, as fiducial models; they are however significant even in the neighborhood of LCDM, where neglecting the degrees of freedom associated with the DE state equation can lead to a misestimate of the matter density parameter \Omega_m.