Solitonic brane inflation

We present a new type of brane inflation motivated by multikink solitonic solutions of a scalar field in five dimensions. In the thin brane limit, we analyze a nonstatic configuration in which the distance between two parallel domain walls decreases. We show that the ensuing spacetime is inflationary, both on the branes, and, for certain potentials, in the bulk. We argue that this inflationary regime is transitory and can end via a brane merger into a single kink solution—a flat, thick brane RS2 universe. This scenario is quite general; we show that any potential which supports a single flat kink solution is also likely to support an inflationary multikink configuration.