Dark Matter and Dark Energy in Spherical Brane-Universe Model

Abstract:

The recent analysis of CMB data combined with other astronomical observations suggests that the universe is nearly flat, but with small positive (spherical) curvature. We show that the model where universe is considered as expanding spherical 3-brane allows us to explain its expansion rate without a dark energy component. In this scenario the computed redshift that corresponds to the transition from cosmic deceleration to acceleration is in a good agreement with observations. Shell-universe model also provides a natural mechanism for local increment of brane tension leading to the modified Newton’s law, alternative to galactic dark matter.