Running non-Gaussianities in Dirac-Born-Infeld inflation

We study the non-Gaussianity in the simplest infrared model of the Dirac-Born-Infeld (DBI) inflation. We show that the non-Gaussianity in such a model is compatible with the current observational bound and is within the sensitivity of future experiments. We also discuss the scale dependence of the non-Gaussianity. In DBI inflation, such a feature can be used as a probe to the properties of the background geometry of the extra dimensions or internal space.