1999/04/02 by Anne-Christine Davis, Matthew Lilley, Ola Törnkvist +1 · 12 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Solar and Space Plasma Dynamics #astro-ph #hep-ph
paper · pdf · doi:10.1103/physrevd.60.021301
published as Phys.Rev.D60:021301,1999 · 5 pages, revtex, 5 figures
arxiv created 1999/04/02 · openalex publication_date 1999/06/23 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We point out that the lower bound on the primordial magnetic field required to seed the galactic dynamo is significantly relaxed in an open universe or in a universe with a positive cosmological constant. In such universes, the increased age of galaxies gives a dynamo mechanism more time to amplify a small initial field. It is shown that, for reasonable cosmological parameters, primordial seed fields of strength 10^\ensuremath-30G or less at the time of galaxy formation could explain observed galactic magnetic fields. As a consequence, mechanisms of primordial magnetic seed-field generation that have previously been ruled out could well be viable. We also comment on the implications of the observation of micro-Gauss magnetic fields in galaxies at high redshift.