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. We show that, within the SC-TH framework, the growth of the structure becomes faster with increasing values of alpha.
R.A.A. Fernandes, J.P.M. de Carvalho, A.Y. Kamenchtchik, U. Moschella, A. da Silva (2012). Spherical "top-hat" collapse in general-Chaplygin-gas-dominated universes. PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY, 85, 083501-083501 [10.1103/PhysRevD.85.083501].
Spherical "top-hat" collapse in general-Chaplygin-gas-dominated universes
KAMENCHTCHIK, ALEXANDR;
2012
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. We show that, within the SC-TH framework, the growth of the structure becomes faster with increasing values of alpha.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
