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Title: STRUCTURE FORMATION BY FIFTH FORCE: POWER SPECTRUM FROM N-BODY SIMULATIONS

Journal Article · · Astrophysical Journal Letters
;  [1];  [2];  [3];  [4]
  1. SUPA, School of Physics and Astronomy, University of St. Andrews, KY16 9SS (United Kingdom)
  2. Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany)
  3. DAMPT, Centre for Mathematical Sciences, University of Cambridge, CB3 0WA (United Kingdom)
  4. Leiden University, Leiden Observatory, Niels-Borhweg 2, 2333CA, Leiden (Netherlands)

We lay out the framework to numerically study nonlinear structure formation in the context of scalar-field-coupled cold dark matter models ({psi}CDM models) where the scalar field {psi} serves as dynamical dark energy. Adopting parameters for the scalar field that leave negligible effects on the cosmic microwave background (CMB) spectrum, we generate the initial conditions for our N-body simulations. The simulations follow the spatial distributions of dark matter and the scalar field, solving their equations of motion using a multilevel adaptive grid technique. We show that the spatial configuration of the scalar field depends sensitively on the local density field. The {psi}CDM model differs from standard {lambda}CDM at small scales with observable modifications of, e.g., the mass function of halos as well as the matter power spectrum. Nevertheless, the predictions of both models for the Hubble expansion and the CMB spectrum are virtually indistinguishable. Hence, galaxy cluster counts and weak lensing observations, which probe structure formation at small scales, are needed to falsify this class of models.

OSTI ID:
21305057
Journal Information:
Astrophysical Journal Letters, Vol. 712, Issue 2; Other Information: DOI: 10.1088/2041-8205/712/2/L179; Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English