The density distributions of cosmic structures: impact of the local environment on weak-lensing convergence

Abstract

Whilst the underlying assumption of the Friedman-Lemaître-Robertson-Walker (FLRW) cosmological model is that matter is homogeneously distributed throughout the universe, gravitational influences over the life of the universe have resulted in mass clustered on a range of scales. Hence we expect that, in our inhomogeneous universe, the view of an observer will be influenced by the location and local environment. Here we analyse the one-point probability distribution functions and angular power spectra of weak-lensing (WL) convergence and magnification numerically to investigate the influence of our local environment on WL statistics in relativistic $N$-body simulations. To achieve this, we numerically solve the null geodesic equations which describe the propagation of light bundles backwards in time from today, and develop a ray-tracing algorithm, and from these calculate various WL properties. Our findings demonstrate how cosmological observations of large-scale structure through WL can be impacted by the locality of the observer. We also calculate the constraints on the cosmological parameters as a function of redshift from the theoretical and numerical study of the angular power spectrum of WL convergence. This study concludes the minimal redshift for the constraint on the parameter ${\Omega }_m$ ($H_0$) is $z\sim 0.2$ $(z\sim 0.6)$ beyond which the local environment's effect is negligible and the data from WL surveys are more meaningful above that redshift. The outcomes of this study will have direct consequences for future surveys, where percent-level-precision is necessary.

11 pages, 10 figures, Accepted to MNRAS

References in corpus (7)

• Array Programming with NumPy
• Full-sky Gravitational Lensing Simulation for Large-area Galaxy Surveys and Cosmic Microwave Background Experiments
• Strong lensing optical depths in a \LambdaCDM universe
• Anti-lensing: the bright side of voids
• Ricci focusing, shearing, and the expansion rate in an almost homogeneous Universe
• 4MOST Scientific Operations
• Impact of our local environment on cosmological statistics

Cited by in corpus (6)

• Cosmological distances with general-relativistic ray tracing: framework and comparison to cosmographic predictions
• Mapping the cosmic mass distribution with stacked weak gravitational lensing and Doppler lensing
• Tracing Cosmological Signature with Doppler Lensing: Insights from Cosmological Simulations
• Weak Lensing Low Multipoles
• Local environmental dependence on weak-lensing shear statistics
• Ringing the universe with cosmic emptiness: void properties through a combined analysis of stacked weak gravitational and Doppler lensing