Structure formation in the presence of dark energy perturbations

By Luis Raul Weber Abramo, R. C. Batista, L. Liberato, Rogerio Rosenfeld. 2007

184 citations recorded by the source corpus.

We study non-linear structure formation in the presence of dark energy. The influence of dark energy on the growth of large-scale cosmological structures is exerted both through its background effect on the expansion rate, and through its perturbations. In order to compute the rate of formation of massive objects we employ the spherical collapse formalism, which we generalize to include fluids with pressure. We show that the resulting non-linear evolution equations are identical to the ones obtained in the pseudo-Newtonian approach to cosmological perturbations, in the regime where an equation of state serves to describe both the background pressure relative to density, and the pressure perturbations relative to the density perturbations. We then consider a wide range of constant and time-dependent equations of state (including phantom models) parametrized in a standard way, and study their impact on the non-linear growth of structure. The main effect is the formation of dark energy structure associated with the dark matter halo: non-phantom equations of state induce the formation of a dark energy halo, damping the growth of structures; phantom models, on the other hand, generate dark energy voids, enhancing structure growth. Finally, we employ the Press–Schechter formalism to compute how dark energy affects the number of massive objects as a function of redshift (number counts).

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/4b8034ec89d32fc40fb2638c9208d1f5efdb26df

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Citations in the corpus

Evolution of cosmological perturbations in Bose–Einstein condensate dark matter (2011, background): “(57) is different from the perturbation equation obtained in the Newtonian cosmology with pressure by Lima et al. (1997), Reis (2003), and Abramo et al. (2007), respectively.”
Formation of Galaxy Clusters (2012, background): “…growth is affected not only because DE influences linear growth, but also because it participates non-trivially in the collapse of matter and may slow down or accelerate the formation of clusters of a given mass depending on DE equation of state (Abramo et al. 2007, Creminelli et al. 2010).”