Paper detail

Cosmology In Terms Of The Deceleration Parameter. Part II

In the early seventies, Alan Sandage defined cosmology as the search for two numbers: Hubble parameter ${{H}_{0}}$ and deceleration parameter ${{q}_{0}}$. The first of the two basic cosmological parameters (the Hubble parameter) describes the linear part of the time dependence of the scale factor. Treating the Universe as a dynamical system it is natural to assume that it is non-linear: indeed, linearity is nothing more than approximation, while non-linearity represents the generic case. It is evident that future models of the Universe must take into account different aspects of its evolution. As soon as the scale factor is the only dynamical variable, the quantities which determine its time dependence must be essentially present in all aspects of the Universe' evolution. Basic characteristics of the cosmological evolution, both static and dynamical, can be expressed in terms of the parameters ${{H}_{0}}$ and ${{q}_{0}}$. The very parameters (and higher time derivatives of the scale factor) enable us to construct model-independent kinematics of the cosmological expansion. Time dependence of the scale factor reflects main events in history of the Universe. Moreover it is the deceleration parameter who dictates the expansion rate of the Hubble sphere and determines the dynamics of the observable galaxy number variation: depending on the sign of the deceleration parameter this number either grows (in the case of decelerated expansion), or we are going to stay absolutely alone in the cosmos (if the expansion is accelerated). The intended purpose of the report is reflected in its title --- "Cosmology in terms of the deceleration parameter". We would like to show that practically any aspect of the cosmological evolution is tightly bound to the deceleration parameter. It is the second part of the report. The first part see here http://arxiv.org/abs/1502.00811