Inflationary magnetogenesis and non-local actions: the conformal anomaly

Journal Article · Mon Feb 01 04:00:00 EST 2016 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2016/02/055· OSTI ID:22524986

We discuss the possibility of successful magnetogenesis during inflation by employing the one-loop effective action of massless QED. The action is strictly non-local and results from the long distance fluctuations of massless charged particles present at the inflationary scale. Most importantly, it encodes the conformal anomaly of QED which is crucial to avoid the vacuum preservation in classical electromagnetism. In particular, we find a blue spectrum for the magnetic field with spectral index n{sub B} ≅ 2 − α{sub e} where α{sub e} depends on both the number of e-folds during inflation as well as the coefficient of the one-loop beta function. In particular, the sign of the beta function has important bearing on the final result. A low reheating temperature is required for the present day magnetic field to be consistent with the lower bound inferred on the field in the intergalactic medium.

• OSTI ID: 22524986
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 02 Vol. 2016; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACTION INTEGRAL
CHARGED PARTICLES
COSMOLOGICAL INFLATION
DISTANCE
ELECTROMAGNETISM
FLUCTUATIONS
INDEXES
INFLATIONARY UNIVERSE
INTERGALACTIC SPACE
MAGNETIC FIELDS
PRESERVATION
QUANTUM ELECTRODYNAMICS