Chaplygin gas with non-adiabatic pressure perturbations
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چکیده
Perturbations in a Chaplygin gas, characterized by an equation of state p = −A/ρ, may acquire non-adiabatic contributions if spatial variations of the parameter A are admitted. This feature is shown to be related to a specific internal structure of the Chaplygin gas. We investigate how perturbations of this type modify the adiabatic sound speed and influence the time dependence of the gravitational potential which gives rise to the Integrated Sachs-Wolfe effect in the anisotropy spectrum of the cosmic microwave background. ‡ Electronic address: [email protected] § Electronic address: [email protected] Chaplygin gas with non-adiabatic pressure perturbations 2
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Perturbations in a Chaplygin gas, characterized by an equation of state p = −A/ρ, may acquire non-adiabatic contributions if spatial variations of the parameter A are admitted. This feature is shown to be related to a specific internal structure of the Chaplygin gas. We investigate how perturbations of this type modify the adiabatic sound speed. A reduction of the effective sound speed compared...
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تاریخ انتشار 2005