“Advanced workshop on cosmological structures: from reionization to galaxies”, ICTP, Trieste, Italy, May 11-15

Abstract:

The cosmic web of large scale structure provides a rich test bed for theories of gravity. The key feature of these theories is their screening mechanism which recovers general relativity on Solar System scales. Using cosmological N-body simulations of modified gravity, I will show that the Vainshtein screening mechanism depends on the cosmic web morphology of dark matter particles identified with ORIGAMI, which defines the structures of the cosmic web according to the dimensionality of their collapse. All halos are screened in the Vainshtein mechanism independent of their mass or environment, while filament, wall, and void particles are unscreened independent of their density. This is in contrast to the chameleon screening mechanism, which depends on both the mass and environment of halos and is not a function of the cosmic web morphology of dark matter particles. I will end by discussing the prospect of using cosmic voids instead of halos to test theories of gravity.