ZhETF, Vol. 147,
p. 709 (April 2015)
(English translation - JETP,
Vol. 120, No. 4,
available online at www.springer.com
SPHERICAL COLLAPSE FOR A VISCOUS GENERALIZED CHAPLYGIN GAS MODEL
Li W., Xu L.
Received: September 2, 2014
The nonlinear collapse for a viscous generalized Chaplygin gas model (VGCG) is analyzed in the framework of spherical top-hat collapse. Because the VGCG and baryons are essential to form the large-scale structure, we focuse on their nonlinear collapse in this paper. We discuss the influence of model parameters α and ζ0 on the spherical collapse by varying their values and compare with the ΛCDM model. The results show that for the VGCG model, smaller ζ0 and larger α make the structure formation earlier and faster, and the collapse curves of the VGCG model are almost coincident with those of the ΛCDM model when the model parameter α is less than 10-2.