Barreira, A. and Bose, S. and Li, B. (2015) 'Speeding up N-body simulations of modified gravity : Vainshtein screening models.', Journal of cosmology and astroparticle physics., 2015 (12). 059.
We introduce and demonstrate the power of a method to speed up current iterative techniques for N-body modified gravity simulations. Our method is based on the observation that the accuracy of the final result is not compromised if the calculation of the fifth force becomes less accurate, but substantially faster, in high-density regions where it is relatively weak due to screening. We focus on the nDGP model which employs Vainshtein screening, and test our method by running AMR simulations in which the fifth force on the finer levels of the mesh (high density) is not obtained iteratively, but instead interpolated from coarser levels. The calculation of the standard gravity component of the force still employs the full AMR structure. We show that the impact this has on the matter power spectrum is below 1% for k < 5h/Mpc at 0z = , and even smaller at higher redshift. The impact on halo properties is also small (lesssim 3% for abundance, profiles, mass; and lesssim 0.05% for positions and velocities). The method can boost the performance of modified gravity simulations by more than a factor of 10. This allows them to run on timescales similar to GR simulations and to push them to resolution levels that were previously hard to achieve.
|Full text:||(AM) Accepted Manuscript|
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|Publisher Web site:||http://dx.doi.org/10.1088/1475-7516/2015/12/059|
|Publisher statement:||This is an author-created, un-copyedited version of an article published 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 10.1088/1475-7516/2015/12/059|
|Date accepted:||14 December 2015|
|Date deposited:||08 April 2016|
|Date of first online publication:||December 2015|
|Date first made open access:||30 December 2016|
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