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Title: Simulating the quartic Galileon gravity model on adaptively refined meshes

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-consistentmore » N-body simulations for these theories.« less
Authors:
; ; ;  [1] ; ;  [2] ;  [3]
  1. Institute for Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)
  2. Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom)
  3. Institute for Particle Physics Phenomenology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)
Publication Date:
OSTI Identifier:
22369938
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2013; Journal Issue: 11; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALGORITHMS; ANISOTROPY; BARYONS; COUPLING; DENSITY; GRAVITATION; MATTER; NONLINEAR PROBLEMS; RELICT RADIATION; SCALAR FIELDS; SIMULATION; SUPERNOVAE; SYMMETRY; VARIATIONS