Fast approximate methods for modified gravity cosmological simulations

Journal Article · 10 February 2020 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/staa333 · OSTI ID:1602297

Vraštil, Michal  ^[1]; Habib, Salman ^[2]

---

1. Department of Astroparticle Physics, Institute of Physics of the Czech Academy of Sciences, Na Slovance 1999/2, CZ-182 21 Prague, Czech Republic
2. CPS and HEP Divisions, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, IL 60439, USA

ABSTRACT The accelerated expansion of the Universe poses a major theoretical puzzle. Although the assumption of a non-zero cosmological constant provides a minimal extension of general relativity that is consistent with observational data, many theories of modified gravity have been suggested as possible alternatives. Predictions of structure formation for these models in the fully non-linear regime are very expensive and it is difficult, if not impossible, to explore such a huge space of models and parameters using high-resolution N-body simulations. Even in the mildly non-linear regime, perturbative methods can become extremely complex. We explore whether simplified dynamical approximations, applicable for a certain set of cosmological probes, can be used to investigate models of modified gravity with acceptable accuracy in the latter instance. For the case of chameleon gravity, we find that these methods can indeed be used to explore the region around the baryon acoustic oscillation scale, $$k\sim 0.1~h\, \text{Mpc}^{-1}$$ but not much further.

• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-06CH11357; W-7405-ENG-36
• OSTI ID: 1602297
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 2 Vol. 493; ISSN 0035-8711
• Publisher: Oxford University PressCopyright Statement
• Country of Publication: United Kingdom
• Language: English