Use of delta N formalism - Difficulties in generating large local-type non-Gaussianity during inflation -

Details Use of delta N formalism - Difficulties in generating large local-type non-Gaussianity during inflation - Use of delta N formalism - Difficulties in generating large local-type non-Gaussianity during inflation -

2010-03-26

arxiv.org/abs/1003.5057v2

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

16 pages, 3 figures, revised version to include the referees' comments, references added.

Scientific paper

We discuss generation of non-Gaussianity in density perturbation through the super-horizon evolution during inflation by using the so-called $\delta N$ formalism. We first provide a general formula for the non-linearity parameter generated during inflation. We find that it is proportional to the slow-roll parameters, multiplied by the model dependent factors that may enhance the non-gaussianity to the observable ranges. Then we discuss three typical examples to illustrate how difficult to generate sizable non-Gaussianity through the super-horizon evolution. First example is the double inflation model, which shows that temporal violation of slow roll conditions is not enough for the generation of non-Gaussianity. Second example is the ordinary hybrid inflation model, which illustrates the importance of taking into account perturbations on small scales. Finally, we discuss Kadota-Stewart model. This model gives an example in which we have to choose rather unnatural initial conditions even if large non-Gaussianity can be generated.

Affiliated with

Also associated with

No associations

Rating

Use of delta N formalism - Difficulties in generating large local-type non-Gaussianity during inflation - does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Use of delta N formalism - Difficulties in generating large local-type non-Gaussianity during inflation -, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Use of delta N formalism - Difficulties in generating large local-type non-Gaussianity during inflation - will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-182060