Exact Four-Dimensional Exploding Universe Solution in String Theory

Shin'ichi Nojiri
1997 Modern Physics Letters A  
We obtain a four dimensional exploding universe solution in string theory. The solution is obtained from the string theory in the flat background by using non-abelian $T$-duality and the analytic continuation. In the solution, the radius of the universe is finite for fixed time and the universe is surrounded with the boundary which is composed of the singularity. The boundary runs away with the speed of light and the flat space-time is left behind.
doi:10.1142/s0217732397001370 fatcat:gnp6jakp2bbqreddqwrjo3pq7e