The Gelaton Scenario: Equilateral non-Gaussianity from multi-field
  dynamics
  The distinctive features of single field inflationary models with non-minimal
kinetic terms, like Dirac-Born-Infeld and k-inflation, can be captured by more
familiar multiple field inflationary systems of the type that typically arise
in low energy supergravity models. At least one heavy field, which we call the
gelaton, has an effective potential which depends on the kinetic energy of the
inflaton. Integrating out the gelaton gives rise to an effectively single field
system for which the speed of sound for the adiabatic fluctuations is reduced,
generating potentially observable equilateral non-Gaussianity, while causing
negligible isocurvature fluctuations. This mechanism is only active if there is
a relatively tight coupling between the gelaton and the inflaton, and this puts
an upper limit on the mass of the gelaton for which the inflaton-gelaton system
remains weakly coupled. This approach gives a UV-completable framework for
describing large classes of k-inflationary behavior.
