Void Lensing in Cubic Galileon Gravity by Chen Su et al. on Monday 21 November
Weak lensing studies via cosmic voids are a promising probe of Modified
Gravity (MG). The Excess Surface mass Density (ESD) is widely used as a lensing
statistics in weak lensing researches. In this paper we use the ray-tracing
method to study the ESD around voids in simulations based on the Cubic Galileon
(CG) gravity. With the compilation of N-body simulation and ray-tracing method,
changes on the structure formation and deflection angle resulting from MG can
both be considered, making the extraction of lensing signals more realistic. We
find good agreements between the measurement and theoretical prediction of ESD
for CG gravity. Meanwhile, the effect on the deflection angle is found to be
incomparable to that on the structure formation in CG, indicating an
equivalence between ESD (statistics) and the projection of 3D dark matter
density field for this gravity. Finally, we demonstrate that it is impossible
to distinguish CG and General Relativity in our simulation with an effective
survey area $\sim1550deg^2$ and a galaxy number density of $10arcmin^{-2}$,
implying that void lensing statistics may not be the optimal probe on testing
CG gravity. The methodology employed in this paper that combines N-body
simulation and ray-tracing method can be a robust way to measure the lensing
signals from simulations based on the MGs, and especially on that who
significantly modifies the deflection angle.
arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.10187v1
