The specific set of six parameters used to define the cosmological model is somewhat open to choice.
Within the context of fitting a ΛCDM model to a CMB power spectrum, the six selected key parameters are primarily chosen to avoid degeneracies and thus speed convergence of the model fit to the data (Kosowsky et al..
Moreover it is the deceleration parameter who dictates the expansion rate of the Hubble sphere and determines the dynamics of the ob- servable 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 .
So, what are the parameters that have been extracted knowing the best data? It is believed that the age of the universe is 13.799 \xb1 0.021 billion years.
The current percentage of the universe that is ordinary matter is 4.86 \xb1 0.10.
The percentage of dark matter is 25.89 \xb1 0.57..
Moreover it is the deceleration parameter who dictates the expansion rate of the Hubble sphere and determines the dynamics of the ob- servable 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 .
