Large-scale magnetic fields, curvature fluctuations, and the thermal history of the Universe

@article{Giovannini2007LargescaleMF,
  title={Large-scale magnetic fields, curvature fluctuations, and the thermal history of the Universe},
  author={Massimo Giovannini},
  journal={Physical Review D},
  year={2007},
  volume={76},
  pages={103508},
  url={https://api.semanticscholar.org/CorpusID:1366157}
}
It is shown that gravitating magnetic fields affect the evolution of curvature perturbations in a way that is reminiscent of a pristine nonadiabatic pressure fluctuation. The gauge-invariant evolution of curvature perturbations is used to constrain the magnetic power spectrum. Depending on the essential features of the thermodynamic history of the Universe, the explicit derivation of the bound is modified. The theoretical uncertainty in the constraints on the magnetic energy spectrum is… 
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