Weak lensing by voids in modified lensing potentials

作者：Barreira Alexandre; Cautun Marius; Li Baojiu; Baugh Carlton M; Pascoli Silvia

来源：Journal of Cosmology and Astroparticle Physics, 2015, 2015(8): 028.

DOI：10.1088/1475-7516/2015/08/028

• modified gravity
• gravitational lensing
• cosmic web
• weak gravitational lensing

We study lensing by voids in Cubic Galileon and Nonlocal gravity cosmologies, which are examples of theories of gravity that modify the lensing potential. We find voids in the dark matter and halo density fields of N-body simulations and compute their lensing signal analytically from the void density profiles, which we show are well fit by a simple analytical formula. In the Cubic Galileon model, the modifications to gravity inside voids are not screened and they approximately double the size of the lensing effects compared to GR. The difference is largely determined by the direct effects of the fifth force on lensing and less so by the modified density profiles. For this model, we also discuss the subtle impact on the force and lensing calculations caused by the screening effects of haloes that exist in and around voids. In the Nonlocal model, the impact of the modified density profiles and the direct modifications to lensing are comparable, but they boost the lensing signal by only approximate to 10%, compared with that of GR. Overall, our results suggest that lensing by voids is a promising tool to test models of gravity that modify lensing.

• 出版日期2015-8