English

Spherical `Top-Hat' Collapse in general Chaplygin gas dominated universes

Cosmology and Nongalactic Astrophysics 2013-05-30 v2

Abstract

We expand previous works on the spherical `top-hat' collapse (SC-TH) framework in generalized Chaplygin gas (gCg) dominated universes. Here we allow the collapse in all energetic components within the system. We analyze the non-linear stages of collapse for various choices of parameter \alpha of the gCg model introducing an exact formulation for the so-called effective sound speed, ceff2c_{eff}^2. We show that, within the SC-TH framework, the growth of the structure becomes faster with increasing values of \alpha.

Cite

@article{arxiv.1110.6205,
  title  = {Spherical `Top-Hat' Collapse in general Chaplygin gas dominated universes},
  author = {R. A. A. Fernandes and J. P. M. de Carvalho and A. Yu. Kamenshchik and U. Moschella and A. da Silva},
  journal= {arXiv preprint arXiv:1110.6205},
  year   = {2013}
}

Comments

17 pages, 5 figures, submitted to Phys. Rev. D. Changes: A new table (Table II) and a new paragraph (at the end of section III.B), were added; Fig. 5 was redrawn and split in two sub-plots, 5a and 5b. We have added a few comments, and a reference, in the introduction; Slight text modifications and typos correction