Deshpande, AC; Taylor, PL; Kitching, TD; (2020) Accessing the high-l frontier under the reduced shear approximation with k-cut cosmic shear. Physical Review D , 102 (8) , Article 083535. 10.1103/PhysRevD.102.083535.

Preview

Text PhysRevD.102.083535.pdf - Published Version Download (835kB) | Preview

Abstract

The precision of Stage IV cosmic shear surveys will enable us to probe smaller physical scales than ever before, however, model uncertainties from baryonic physics and non-linear structure formation will become a significant concern. The k-cut method - applying a redshift-dependent-cut after making the Bernardeau-Nishimichi-Taruya transform - can reduce sensitivity to baryonic physics; allowing Stage IV surveys to include information from increasingly higher-modes. Here we address the question of whether it can also mitigate the impact of making the reduced shear approximation; which is also important in the high-κ, small-scale regime. The standard procedure for relaxing this approximation requires the repeated evaluation of the convergence bispectrum, and consequently can be prohibitively computationally expensive when included in Monte Carlo analyses. We find that the k-cut cosmic shear procedure suppresses the w_{0}w_{a} CDM cosmological parameter biases expected from the reduced shear approximation for Stage IV experiments, when-modes up to 5000 are probed. The maximum cut required for biases from the reduced shear approximation to be below the threshold of significance is at k=5.37 h Mpc^{-1}. With this cut, the predicted 1σ constraints increase, relative to the case where the correction is directly computed, by less than 10% for all parameters. This represents a significant improvement in constraints compared to the more conservative case where only-modes up to 1500 are probed [A. Blanchard, (Euclid Collaboration), arXiv:1910.09273], and no k-cut is used. We also repeat this analysis for a hypothetical, comparable kinematic weak lensing survey. The key parts of code used for this analysis are made publicly available.

Download activity - last month

Export as XMLJSONCSV

Download activity - last 12 months

Export as CSVXMLJSON

Downloads by country - last 12 months

Export as CSVJSONXML

Archive Staff Only

View Item