Tachyonic Inflation

It is well known that inflation provides the most compelling solution to many long-standing problems of the big bang model (horizon, flatness, monopoles, etc.) The source of inflation is a scalar field (the inflaton field), which in light of modern theories, can be based on a Dirac-Borne-Infeld action rather than the conventional Klein-Gordon action, allowing the inflaton field to take the form of a tachyon field. A rolling tachyon field is usually associated with unstable D-brane configurations, where decay of such D-branes (via tachyon condensation) produces a pressureless gas with finite energy density resembling classical dust. In their April 6th paper (arXiv:0904.1032v1), del Campo et al. investigate such a tachyonic inflationary universe model in the context of intermediate inflation.