2013/06/29 by Luiz Carlos Garcia de Andrade, de Andrade, Luiz Carlos Garcia · 1 citation
Biochemistry, Genetics and Molecular Biology · Earth and Planetary Sciences · Physics and Astronomy · #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geomagnetism and Paleomagnetism Studies #Geophysics and Gravity Measurements #Solar and Space Plasma Dynamics #astro-ph.CO #gr-qc
paper · pdf · doi:10.48550/arxiv.1307.0142
Dept of theoretical physics, UERJ, Brasil
arxiv created 2013/06/29 · openalex publication_date 2013/06/29 · arxiv updated 2013/07/02 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Earlier Bamba et al [JCAP (2012)] have obtained cosmological magnetic fields in teleparallel torsion theories of gravity that are not compatible with galactic dynamos. This result agrees with previous ones obtained by the author which shows [Phys Lett B (2012)] that anti-dynamo generalised theorem to torsion theories forbides such kind of dynamos to explain galactic magnetic fields of the order of μG. More recently the author has suggested [IJAA (2012)] that a sort of Biermann battery could be obtained in torsioned cosmology. Nevertheless in this paper we show that this can be a particular result, since the second author did not took into account mean field dynamo equations in torsion field background. Actually it is shown that amplification or not of the magnetic field depends upon handness sign of the torsion field vector. It is shown that density fluctuations of spin-torsion density implies also a possibility of amplification of the cosmic magnetic fields. From WMAP data it is possible to estimate the spin-torsion fluctuation as 10-6 which represents an order of magnitude lower than the matter density. By making use of the gravitational couling of type RF2 one obtains 1037G for the Planck era magnetic field, which is a much more stringent limit than the ones obtained earlier. The magnetic field obtained today is 10-23G is obtained which is able to seed galactic dynamos.