1. Clear and Measurable Signature of Modified Gravity in the Galaxy Velocity Field.
- Author
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Hellwing, Wojciech A., Barreira, Alexandre, Erenk, Carlos S., Baojiu Li, and Cole, Shaun
- Subjects
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FLOW velocity , *FLUID dynamics , *DARK matter , *GALAXIES , *N-body simulations (Astronomy) , *VELOCITY distribution (Statistical mechanics) , *STATISTICAL mechanics - Abstract
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 f(R) 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. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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