Articulo
The Santiago-Harvard-Edinburgh-Durham void comparison II: unveiling the Vainshtein screening using weak lensing
Fecha
2019Registro en:
1150300
WOS:000462293100080
Institución
Resumen
We study cosmic voids in the normal-branch Dvali-Gabadadze-Porrati (nDGP) braneworld models that are representative of a class of modified gravity theories where deviations from General Relativity are usually hidden by the Vainshtein screening in high-density environments. This screening is less efficient away from these environments, which makes voids ideally suited for testing this class of models. We use N-body simulations of Lambda-cold dark matter (Lambda CDM) and nGDP universes, where dark matter haloes are populated with mock galaxies that mimic the clustering and number densities of the Boss CMASS galaxy sample. We measure the force, density, and weak lensing profiles around voids identified with six different algorithms. Compared to Lambda CDM, voids in nDGP are more underdense due to the action of the fifth force that arises in these models, which leads to a faster evacuation of matter from voids. This leaves an imprint on the weak lensing tangential shear profile around nDGP voids, an effect that is particularly strong for 2D underdensities that are identified in the plane of the sky. We make predictions for the feasibility of distinguishing between nDGP and Lambda CDM using void lensing in upcoming large-scale surveys such as LssT and EUCLID. We compare with the analysis of voids in chameleon gravity theories and find that the weak lensing signal for 3D voids is similar to nDGP, whereas for 2D voids the differences with Lambda CDM are much stronger for the chameleon gravity case, a direct consequence of the different screening mechanisms operating in these theories.