Skip to main content
Hubble slow roll expansion for multifield inflation
Physical Review D
  • John T. Giblin, Kenyon College
  • Richard Easther
Document Type
Publication Date
We examine the dynamics of inflation driven by multiple, interacting scalar fields and derive a multifield version of the Hubble slow roll expansion. We show that the properties of this expansion naturally generalize those of the single field case. We present an analogous hierarchy of slow roll parameters, and derive the system of flow equations that describes their evolution, and show that when this system is truncated at finite order, it can always be solved exactly. Lastly, we express the scalar and tensor perturbation spectra in terms of the slow roll parameters.
Citation Information
John T. Giblin and Richard Easther. "Hubble slow roll expansion for multifield inflation" Physical Review D Vol. 72 (2005)
Available at: