Abstract
We investigate the dynamics of dust matter with bulk viscosity effects. We explored the analogy dynamical problem to Chaplygin gas. Due to this analogy we give exact solutions for the FRW cosmology with viscosity coefficient parameterized by the Belinskii–Khalatnikov power law dependence with respect to energy density. These exact solutions are given in the form of hypergeometrical functions. We proved simple theorem which illustrated as viscosity effects can solved the initial singularity problem present in standard cosmological model.
Highlights
The viscous fluid is an important subject of study in fluid mechanics [1], but starting from the 1960s this idea becomes attractive in cosmology, too
Murphy studied bulk viscosity effects in FRW cosmology and demonstrated that the constant bulk viscosity can solve the problem of an initial singularity in the FRW cosmology [6]
We explored an analogy of viscous FRW models with the FRW equation with Chaplygin gas
Summary
The viscous fluid is an important subject of study in fluid mechanics [1], but starting from the 1960s this idea becomes attractive in cosmology, too. In contemporary cosmology the effect of acceleration of the current Universe is investigated in terms of the standard cosmological model or ΛCDM model In this model role of substantial dark energy assumes the cosmological constant parameter Λ. We can describe exactly a current state of the Universe but we cannot explain why the value of the cosmological constant is so small Another difficulty of the ΛCDM model is the explanation why density parameters for dark energy and matter are comparable? The contemporary studies of viscous cosmological models are related to investigation of inflation [12], dark matter and dark energy problem, singularities etc. The idea of Chaplygin gas is attractive [14] because in the cosmological context it unifies effectively both dark matter (pressure) and dark energy (the parameter Λ) [15,16].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
