Observable non-gaussianity from gauge field production in slow roll inflation, and a challenging connection with magnetogenesis

Details Observable non-gaussianity from gauge field production in slow roll inflation, and a challenging connection with magnetogenesis Observable non-gaussianity from gauge field production in slow roll inflation, and a challenging connection with magnetogenesis

2012-02-07

arxiv.org/abs/1202.1469v2

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

25 pages, no figures. Improved discussion of the shape of the bispectrum. References added

Scientific paper

In any realistic particle physics model of inflation, the inflaton can be expected to couple to other fields. We consider a model with a dilaton-like coupling between a U(1) gauge field and a scalar inflaton. We show that this coupling can result in observable non-gaussianity, even in the conventional regime where inflation is supported by a single scalar slowly rolling on a smooth potential: the time dependent inflaton condensate leads to amplification of the large-scale gauge field fluctuations, which can feed-back into the scalar/tensor cosmological perturbations. In the squeezed limit, the resulting bispectrum is close to the local one, but it shows a sizable and characteristic quadrupolar dependence on the angle between the shorter and the larger modes in the correlation. Observable non-gaussianity is obtained in a regime where perturbation theory is under control. If the gauge field is identified with the electromagnetic field, the model that we study is a realization of the magnetogenesis idea originally proposed by Ratra, and widely studied. This identification (which is not necessary for the non-gaussianity production) is however problematic in light of a strong coupling problem already noted in the literature.

Affiliated with

Also associated with

No associations

Rating

Observable non-gaussianity from gauge field production in slow roll inflation, and a challenging connection with magnetogenesis 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 Observable non-gaussianity from gauge field production in slow roll inflation, and a challenging connection with magnetogenesis, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Observable non-gaussianity from gauge field production in slow roll inflation, and a challenging connection with magnetogenesis will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-579671