A clear and measurable signature of modified gravity in the galaxy velocity field

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, $v_{12}$, are a powerful diagnostic of the laws of gravity on cosmological scales. In particular, the projected line-of-sight galaxy pairwise velocity dispersion, ${\sigma }_{12}(r)$, 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 $(5-10)\sigma$ 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.

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

References in corpus (7)

• Models of f(R) Cosmic Acceleration that Evade Solar-System Tests
• Covariant Galileon
• Generalized Galileons: All scalar models whose curved background extensions maintain second-order field equations and stress tensors
• A test of the nature of cosmic acceleration using galaxy redshift distortions
• The 2dF-SDSS LRG and QSO survey: evolution of the clustering of luminous red galaxies since z = 0.6
• Halo model and halo properties in Galileon gravity cosmologies
• Dark Matter Gravitational Clustering With a Long-Range Scalar Interaction

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• The effect of baryons on redshift space distortions and cosmic density and velocity fields in the EAGLE simulation
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• The Novel Probes Project -- Tests of Gravity on Astrophysical Scales
• Extending cosmological tests of General Relativity with the Square Kilometre Array
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• Improving the modelling of redshift-space distortions - II. A pairwise velocity model covering large and small scales
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• Testing General Relativity with the Doppler magnification effect
• A New Dynamical Mass Measurement for the Virgo Cluster using the Radial Velocity Profile of the Filament Galaxies
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• Estimates of cluster masses in screened modified gravity
• Singling out modified gravity parameters and datasets reveals a dichotomy between Planck and lensing
• N-body Simulations of $\gamma$ Gravity
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• Dynamics of pairwise motions in the fully non-linear regime in LCDM and Modified Gravity cosmologies
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