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

Abstract

We obtain a \textit{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\cite{E1,E2,E3} 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 \textit{first} model where a single braneworld of positive tension can be made to recycle as discussed in details in the concluding section.