11,878 research outputs found
Seed Magnetic Fields Generated by Primordial Supernova Explosions
The origin of the magnetic field in galaxies is an open question in
astrophysics. Several mechanisms have been proposed related, in general, with
the generation of small seed fields amplified by a dynamo mechanism. In
general, these mechanisms have difficulty in satisfying both the requirements
of a sufficiently high strength for the magnetic field and the necessary large
coherent scales. We show that the formation of dense and turbulent shells of
matter, in the multiple explosion scenario of Miranda and Opher (1996, 1997)
for the formation of the large-scale structures of the Universe, can naturally
act as a seed for the generation of a magnetic field. During the collapse and
explosion of Population III objects, a temperature gradient not parallel to a
density gradient can naturally be established, producing a seed magnetic field
through the Biermann battery mechanism. We show that seed magnetic fields can be produced in this multiple explosion scenario on
scales of the order of clusters of galaxies (with coherence length ) and up to on scales of galaxies ().Comment: Accepted for publication in MNRAS, 5 pages (MN plain TeX macros v1.6
file). Also available at http://www.iagusp.usp.br/~oswaldo (click "OPTIONS"
and then "ARTICLES"
Electron-polaron--electron-polaron bound states in mass-gap graphene-like planar quantum electrodynamics: -wave bipolarons
A Lorentz invariant version of a mass-gap graphene-like planar quantum
electrodynamics, the parity-preserving massive QED,
exhibits attractive interaction in low-energy
electron-polaron--electron-polaron -wave scattering, favoring quasiparticles
bound states, the -wave bipolarons.Comment: 6 pages, two figures, references adde
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