Apparent Acceleration through the Large-scale Inhomogeneities Post-Friedmannian effects of inhomogeneities on the luminosity distance

We re-analyze the observed magnitude-redshift relation of type Ia supernovae (SNe Ia) and examine the possibility that the apparent acceleration of the cosmic expansion is not caused by dark energy, but is a consequence of large-scale inhomogeneities in the universe. We propose a method to describe phenomenologically the effects of the large-scale inhomogeneities, without depending on the specific toy models of the inhomogeneous universe. This method clearly illustrates how the post-Friedmannian effects of inhomogeneities, i.e., the effects due to the deviations from the perfectly homogeneous and isotropic model, act as an effective cosmological constant in the magnitude-redshift relation of SNe Ia.