Property of recombination in polarized hadronic targets

Berera, Arjun

doi:10.1103/physrevd.50.6730

Cited by 1 publication

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References 9 publications

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“…Unfortunately more recently we showed [6] that the magnetic field decayed fast enough not to be able to seed galactic dynamos. Earlier, Barrow and Tsagas [7] showed that in open Friedmann universes, magnetic fields decay slower, therefore this mechanism is able to help obtaining cosmic magn etic fields strong enough to seed the galactic dynamo beyond inflation [8]. Even earlier, Turner and Widrow [1] proposed a Lagrangean in pseudo-Riemannian spacetime to generate primordial magnetic fields which could obtain extremely weak seed fields of the order of 10 −65 G through the presence of a tiny photon mass, which clearly are extremely weak to seed galactic dynamos.…”

Section: Introductionmentioning

confidence: 99%

Large scale magnetic fields from torsion modes and massive photon inflation

Andrade

2017

Class. Quantum Grav.

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Previously, Barrow and Tsagas (2008 Phys. Rev. D 77 107302) showed that a slower decay of magnetic fields are present in open Friedmann universes, with traditional Maxwell equations. In their paper magnetic fields of the order of , which are far below the value required to seed galactic dynamos, were obtained. In this paper, galactic dynamo seeds of the order of are obtained from massive electrodynamics in an Einstein–Cartan–Proca expanding universe of de Sitter type. Slow decay of magnetic fields in photon–torsion coupling in quantum electrodynamics (Garcia de Andrade 2011 Phys. Lett. B 468 28) have been recently shown by the author Garcia de Andrade (2012 Phys. Lett. B 711 143) to also not be able to seed galactic dynamos. Torsion modes are constrained by the field equations. Spacetime torsion is shown to be explicitly responsible for the slow decay of a cosmic magnetic field. In the absence of massive photon torsion coupling the magnetic field decay is of the order , when torsion turns on . The pure massive-photon–torsion contribution amplifies the magnetic field by which characterizes an extremely slow magnetic dynamo action due to purely torsion gravitational effects. Recently Barrow, Tsagas and Yamamoto (2012 Phys. Rev. D 86 023535) have obtained superadiabatic amplification of B-fields in Friedmann open cosmology which lies within and which falls very comfortably within the limits to seed galactic dynamos. The are other simple solutions where a B-field decays as , a relatively weak photon–torsion coupling approximation. These solutions are obtained for de Sitter and Friedmann metrics. Numerical values as displayed in this new version of the paper specifically for GUT phases of inflation with and without massive photons; without photons we obtain the well known value of GR which is while for the values with massive photons one obtains . At the present time one obtains and with massive photons one obtains , which is unfortunately much stronger than the value obtained by astronomical observations of .

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Section: Introductionmentioning

confidence: 99%

Large scale magnetic fields from torsion modes and massive photon inflation

Andrade

2017

Class. Quantum Grav.

View full text Add to dashboard Cite

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Property of recombination in polarized hadronic targets

Cited by 1 publication

References 9 publications

Large scale magnetic fields from torsion modes and massive photon inflation

Large scale magnetic fields from torsion modes and massive photon inflation

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