Growth of perturbations in an expanding universe with Bose-Einstein condensate dark matter

By Pierre-Henri Chavanis. 2011

145 citations recorded by the source corpus.

We study the growth of perturbations in an expanding Newtonian universe with Bose-Einstein condensate (BEC) dark matter. We first ignore special relativistic effects and derive a differential equation that governs the evolution of the density contrast in the linear regime. This equation, which takes quantum pressure and self-interaction into account, can be solved analytically in several cases. We argue that an attractive self-interaction can enhance the Jeans instability and fasten the formation of structures. Then, we take pressure effects (coming from special relativity) into account in the evolution of the cosmic fluid and add the contribution of radiation, baryons, and dark energy (cosmological constant). For BEC dark matter with repulsive self-interaction (positive pressure) the scale factor increases more rapidly than in the standard ΛCDM model where dark matter is pressureless, while it increases less rapidly for BEC dark matter with attractive self-interaction (negative pressure). We study the linear development of the perturbations in these two cases and show that the perturbations grow faster in BEC dark matter than in pressureless dark matter. Finally, we consider a “dark fluid” with a generalized equation of state p = (αρ + kρ 2 )c 2 having a component p = kρ 2 c 2 similar to BEC dark matter and a component p = αρc 2 mimicking the effect of the cosmological constant (dark energy). We find optimal parameters that give good

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/402a15246fe478babd8bd45209e734dc90bffcf6

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Citations in the corpus

Do dark matter axions form a condensate with long-range correlation? (2014, background): “The latter is a hypothesized particle introduced to solve the CP problem in QCD [3–5].”
Angular Momentum and Vortex Formation in Bose-Einstein-Condensed Cold Dark Matter Haloes (2011, result): “Some recent results on structure formation studies involving BEC-CDM can be found in the works of Ureña-López & Guzmán (2003); Fukuyama, Morikawa & Tatekawa (2008); Woo & Chiueh (2009); Marsh & Ferreira (2010); Harko (2011) and Chavanis (2012)3.”
Dynamical boson stars (2012, background): “(58) which involves a pseudo-potential for a Bose–Einstein condensate, to model either dark matter or compact alternatives to neutron stars [46, 47, 48].”