Structure formation by the fifth force: Segregation of baryons and dark matter
- Centre for Theoretical Cosmology, DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)
- SUPA, University of St. Andrews, North Haugh, Fife, KY16 9SS (United Kingdom)
In this paper we present the results of N-body simulations with a scalar field coupled differently to cold dark matter (CDM) and baryons. The scalar field potential and coupling function are chosen such that the scalar field acquires a heavy mass in regions with high CDM density and thus behaves like a chameleon. We focus on how the existence of the scalar field affects the formation of nonlinear large-scale structures, and how the different couplings of the scalar field to baryons and CDM particles lead to different distributions and evolutions for these two matter species, both on large scales and inside virialized halos. As expected, the baryon-CDM segregation increases in regions where the fifth force is strong, and little segregation in dense regions. We also introduce an approximation method to identify the virialized halos in coupled scalar field models which takes into account the scalar field coupling and which is easy to implement numerically. It is found that the chameleon nature of the scalar field makes the internal density profiles of halos dependent on the environment in a very nontrivial way.
- OSTI ID:
- 21409758
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 81, Issue 10; Other Information: DOI: 10.1103/PhysRevD.81.104047; (c) 2010 The American Physical Society; ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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