ECOSMOG: an Efficient COde for Simulating MOdified Gravity

Journal Article · Sun Jan 01 04:00:00 EST 2012 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2012/01/051· OSTI ID:22280192

Li, Baojiu ^[1]; Zhao, Gong-Bo; Koyama, Kazuya ^[2]; Teyssier, Romain ^[3]

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1. ICC, Physics Department, University of Durham, South Road, Durham DH1 3LE (United Kingdom)
2. Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom)
3. Universität Zürich, Institute für Theoretische Physik, Winterthurerstrasse 190, CH-8057 Zürich (Switzerland)

We introduce a new code, ECOSMOG, to run N-body simulations for a wide class of modified gravity and dynamical dark energy theories. These theories generally have one or more new dynamical degrees of freedom, the dynamics of which are governed by their (usually rather nonlinear) equations of motion. Solving these non-linear equations has been a great challenge in cosmology. Our code is based on the RAMSES code, which solves the Poisson equation on adaptively refined meshes to gain high resolutions in the high-density regions. We have added a solver for the extra degree(s) of freedom and performed numerous tests for the f(R) gravity model as an example to show its reliability. We find that much higher efficiency could be achieved compared with other existing mesh/grid-based codes thanks to two new features of the present code: (1) the efficient parallelisation and (2) the usage of the multigrid relaxation to solve the extra equation(s) on both the regular domain grid and refinements, giving much faster convergence even under much more stringent convergence criteria. This code is designed for performing high-accuracy, high-resolution and large-volume cosmological simulations for modified gravity and general dark energy theories, which can be utilised to test gravity and the dark energy hypothesis using the upcoming and future deep and high-resolution galaxy surveys.

• OSTI ID: 22280192
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 01 Vol. 2012; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
COSMOLOGY
DEGREES OF FREEDOM
E CODES
EQUATIONS OF MOTION
GALAXIES
GRAVITATION
NONLINEAR PROBLEMS
NONLUMINOUS MATTER
POISSON EQUATION
RELAXATION
RELIABILITY