2014/01/31 by Wojciech A. Hellwing, Alexandre Barreira, Carlos S. Frenk +2 · 1 citation
Physics and Astronomy · #astro-ph.CO
paper · pdf · doi:10.1103/physrevlett.112.221102
published as Phys. Rev. Lett. 112, 221102 (2014) · 5 pages, 2 figures, accepted for publication in Physical Review Letters. Minor changes to text, some references added. The Fig. 1 now presents results for HOD LRG galaxy mock catalogues, the comments in the text changed accordingly
arxiv created 2014/06/10 · arxiv updated 2014/06/11
The velocity field of dark matter and galaxies reflects the continued action of gravity throughout cosmic history. We show that the low-order moments of the pairwise velocity distribution, v12, are a powerful diagnostic of the laws of gravity on cosmological scales. In particular, the projected line-of-sight galaxy pairwise velocity dispersion, σ12(r), is very sensitive to the presence of modified gravity. Using a set of high-resolution N-body simulations we compute the pairwise velocity distribution and its projected line-of-sight dispersion for a class of modified gravity theories: the chameleon \fR gravity and Galileon gravity (cubic and quartic). The velocities of dark matter halos with a wide range of masses would exhibit deviations from General Relativity at the (5-10)σ level. We examine strategies for detecting these deviations in galaxy redshift and peculiar velocity surveys. If detected, this signature would be a "smoking gun" for modified gravity.