Nonlinear evolution of f(R) cosmologies. I. Methodology

Journal Article · Mon Dec 15 04:00:00 EST 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.78.123523· OSTI ID:21251112

Oyaizu, Hiroaki ^[1]

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1. Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois 60637 (United States)

We introduce the method and the implementation of a cosmological simulation of a class of metric-variation f(R) models that accelerate the cosmological expansion without a cosmological constant and evade solar-system bounds of small-field deviations to general relativity. Such simulations are shown to reduce to solving a nonlinear Poisson equation for the scalar degree of freedom introduced by the f(R) modifications. We detail the method to efficiently solve the nonlinear Poisson equation by using a Newton-Gauss-Seidel relaxation scheme coupled with the multigrid method to accelerate the convergence. The simulations are shown to satisfy tests comparing the simulated outcome to analytical solutions for simple situations, and the dynamics of the simulations are tested with orbital and Zeldovich collapse tests. Finally, we present several static and dynamical simulations using realistic cosmological parameters to highlight the differences between standard physics and f(R) physics. In general, we find that the f(R) modifications result in stronger gravitational attraction that enhances the dark matter power spectrum by {approx}20% for large but observationally allowed f(R) modifications. A more detailed study of the nonlinear f(R) effects on the power spectrum are presented in a companion paper.

• OSTI ID: 21251112
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 12 Vol. 78; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
ANALYTICAL SOLUTION
CONVERGENCE
COSMOLOGICAL CONSTANT
COSMOLOGICAL MODELS
COSMOLOGY
DEGREES OF FREEDOM
EVOLUTION
EXPANSION
GENERAL RELATIVITY THEORY
METRICS
MODIFICATIONS
NONLINEAR PROBLEMS
NONLUMINOUS MATTER
POISSON EQUATION
RELAXATION
SIMULATION
SOLAR SYSTEM
SPECTRA