A novel model of non-singular oscillating cosmology on flat Randall–Sundrum II braneworld

Abstract

We obtain a novel model of oscillating non-singular cosmology on the spatially flat Randall–Sundrum (RS) II brane. At early times, the universe is dominated by a scalar field with an inflationary emergent potential \(V(\phi )=A(e^{B\phi }-1)^2\) , A and B being constants. Interestingly, we find that such a scalar field can source a non-singular bounce, replacing the big bang on the brane. The turnaround again happens naturally on the brane dominated by a phantom dark energy [favoured by observations (Knop et al. in Astrophys J 598:102, 2003. Spergel et al. in Astrophys J Suppl 148:175, 2003. Tegmark et al. in Phys Rev D 69:103501, 2004) at late times], thus avoiding the big rip singularity and leading upto the following non-singular bounce via a contraction phase. There is a smooth non-singular transition of the brane universe through both the bounce and turnaround, leading to alternate expanding and contracting phases. This is the first model where a single braneworld of positive tension can be made to recycle as discussed in details in the concluding section.