In the combined theory of Special Relativity and Quantum Mechanics (c-SRQM), the upper limit of local acceleration is constrained to c2/A, where c is the speed of light and A is the diameter of the event horizon of the smallest black hole in nature - called the Unit Black Hole (UBH). In this article, a new cosmological model is proposed wherein the flatness of the universe is inevitable from the onset. The theory indicates that at any given moment of the cosmic evolution, the age of the universe can be expressed as some integer multiple of the cosmological time constant A/c. The integer multiple 1, signifies the end of the Big Bang at which the initial conditions undergo a sudden change. The known universe is then shown to be the observable portion of a much bigger structure - named the grand universe - which is originated from a Primordial Black Hole (PBH) expanding with the limit rate c2/A at time A/c. It is shown that the dipole in the Cosmic Microwave Background (CMB) could be explained by the anisotropy in the gravitational redshift of the grand universe. Moreover, a best fit to the observational Hubble diagram is obtained when the absolute luminosity of type Ia supernovae is constrained to 3.02e9 times that of the sun. The age of the universe is found to be 15.96e9 (years). The new age is higher than that of the standard cosmology by 2.14e9 (years), therefore, reducing the age discrepancy between the universe and the old metal-deficient stars. The actual value of the Hubble constant Ho is found to be 40.83 (km/sec/Mpc). The discrepancy with the current estimates of the constant is due to neglecting the gravitational redshift of the grand universe in the current standard cosmology.