A Proposed Cosmological Model to Explain the Accelerating Expansion and its Coincidence with the Observational Data

The aim of this research is to provide an explanation for the cosmic acceleration of a derived model (flat model which contains both matter and dark energy (NR + DE = 1). This model depends on two different models, one contains matter only NR=1 while the other contains dark energy DE = 1. The derived model shows a good matching with the observed data of supernovae type Ia. The relationships of the three models that link the illumination distance and distance modulus were drawn against redshift for the given observational data, which show that the flat universe is the closest to the observational data. It turned out that the amount of the relative density of the dark energy DE is larger than the amount of the relative density of matter NR. This result is considered as an explanation of the cosmic acceleration due to the presence of dark energy