Li, B. and Barreira, A. and Baugh, C. M. and Hellwing, W. A. and Koyama, K. and Pascoli, S. and Zhao, G. (2013) 'Simulating the quartic Galileon gravity model on adaptively refined meshes.', Journal of cosmology and astroparticle physics., 2013 (11). 012.
We develop a numerical algorithm to solve the high-order nonlinear derivative-coupling equation associated with the quartic Galileon model, and implement it in a modified version of the ramses N-body code to study the effect of the Galileon field on the large-scale matter clustering. The algorithm is tested for several matter field configurations with different symmetries, and works very well. This enables us to perform the first simulations for a quartic Galileon model which provides a good fit to the cosmic microwave background (CMB) anisotropy, supernovae and baryonic acoustic oscillations (BAO) data. Our result shows that the Vainshtein mechanism in this model is very efficient in suppressing the spatial variations of the scalar field. However, the time variation of the effective Newtonian constant caused by the curvature coupling of the Galileon field cannot be suppressed by the Vainshtein mechanism. This leads to a significant weakening of the strength of gravity in high-density regions at late times, and therefore a weaker matter clustering on small scales. We also find that without the Vainshtein mechanism the model would have behaved in a completely different way, which shows the crucial role played by nonlinearities in modified gravity theories and the importance of performing self-consistent N-body simulations for these theories.
|Keywords:||Modified gravity, Power spectrum, Cosmological simulations, Dark energy theory.|
|Full text:||(NA) Not Applicable |
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|Publisher Web site:||http://iopscience.iop.org/1475-7516/2013/11/012/|
|Publisher statement:||This is an author-created, un-copyedited version of an article accepted for publication in Journal of Cosmology and Astroparticle Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://iopscience.iop.org/1475-7516/2013/11/012/.|
|Date accepted:||No date available|
|Date deposited:||No date available|
|Date of first online publication:||November 2013|
|Date first made open access:||No date available|
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