“School of Physics”

Back to Papers Home
Back to Papers of School of Physics

Paper   IPM / P / 12185
School of Physics
  Title:   1/N Resolution to Inflationary η-Problem
1.  A . Ashoorioon
2.  U. Danielsson
3.  M.M. Sheikh-Jabbari
  Status:   Published
  Journal: Phys. Lett. B
  Vol.:  713
  Year:  2012
  Pages:   353
  Supported by:  IPM
We observe that the dominant one loop contribution to the graviton propagator in the theory of N (N >> 1) light scalar fields ϕa (with masses smaller than \mpl/√N) minimally coupled to Einstein gravity is proportional to N while that of graviton-scalar-scalar interaction vertex is N independent. We use this to argue that the coefficient of Rϕa2 term appearing at one loop level is 1/N suppressed. This observation provides a resolution to the η-problem, that the slow-roll parameter η receives order one quantum loop corrections for inflationary models built within the framework of scalar fields minimally coupled to Einstein gravity, for models involving large number of fields. As particular examples, we employ this to argue in favor of the absence of η-problem in M-flation and N-flation scenarios.

Download TeX format
back to top
scroll left or right