Magnetogenesis and the primordial non-gaussianity

Journal Article · Sat Aug 01 04:00:00 EDT 2009 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2009/08/018· OSTI ID:22273226

Seery, David ^[1]

---

1. Department of Applied Mathematics and Theoretical Physics, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)

The primordial density fluctuation inevitably couples to all forms of matter via loop corrections and depends on the ambient conditions while inflation was ongoing. This gives us the opportunity to observe processes which were in progress while the universe was inflating, provided they were sufficiently dramatic to overcome suppression by powers of (H/M{sub P}){sup 2} ≈ 10{sup −9}, where H is the Hubble scale during inflation and M{sub P} is the Planck mass. As an example, if a primordial magnetic field was synthesized during inflation, as suggested by some interpretations of the apparently universal 10{sup −6} gauss field observed on galactic scales, then this could leave traces in inflationary observables. In this paper, I compute corrections to the spectrum and bispectrum generated by a varying electromagnetic coupling during inflation, assuming that the variation in this coupling is mediated by interaction with a collection of light scalar fields. If the mass scale associated with this interaction is too far below the Planck scale then the stability of perturbation theory can be upset, potentially leading to a large non-gaussianity which would be incompatible with observation. For the mass-scale which is relevant in the standard magnetogenesis scenario, however, the theory is stable and the model is apparently consistent with observational constraints.

• OSTI ID: 22273226
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 08 Vol. 2009; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CORRECTIONS
COSMOLOGY
COUPLING
FLUCTUATIONS
INFLATIONARY UNIVERSE
INFLATONS
LIMITING VALUES
MAGNETIC FIELDS
POTENTIALS
SCALAR FIELDS
UNIVERSE
VISIBLE RADIATION