The effects of structure anisotropy on lensing observables in an exact general relativistic setting for precision cosmology

Understand

The study of relativistic, higher order and nonlinear effects has become necessary in recent years in the pursuit of precision cosmology.

• We develop and apply here a framework to study gravitational lensing in exact models in general relativity that are not restricted to homogeneity and isotropy, and where full nonlinearity and relativistic effects are included.
• We apply the framework to a specific, anisotropic galaxy cluster model which is based on a modified NFW halo density profile and described by the Szekeres metric.
• We examine the effects of increasing levels of anisotropy in the galaxy cluster on lensing observables like the convergence and shear for various lensing geometries, finding a strong nonlinear response in both the convergence and shear for rays passing through anisotropic regions of the cluster.